diff --git a/README.md b/README.md
index 402f7a0..cb85f2e 100644
--- a/README.md
+++ b/README.md
@@ -31,16 +31,32 @@ der Browserstandort wäre dann das Wohnzimmer statt der Messe. Die Koordinaten
 löst Nominatim in einen Ortsnamen auf. Fehlen EXIF-Daten, greift der
 Browserstandort als Rückfallebene.
 
-**Übersicht.** Alle Karten mit Volltextsuche über Name, Firma, Ort und Notiz.
-Filter für „nicht exportiert“, „unvollständig“ und „mit Erinnerung“.
+**Anlass.** Ein Feld auf der Startseite („Hannover Messe 2026“) gilt für alle
+folgenden Scans und wird im Browser gemerkt. Verlässlicher als der Ortsname aus
+den Koordinaten und die eigentliche Ordnung über den Bestand.
 
-**Export.** Ein Tippen auf *In Kontakte speichern* liefert eine vCard 3.0, die
-iOS direkt in die Kontakte-App übernimmt. Die Karte gilt danach als exportiert.
-Bewusst einzeln: ein Sammelexport schiebt zwanzig Kontakte ungeprüft ins
-Adressbuch.
+**Dubletten.** Auf Messen trifft man Leute wieder. Die Detailansicht zeigt
+Karten, die dieselbe Person meinen könnten – gleiche E-Mail, gleiche
+Telefonnummer (Schreibweise egal, verglichen werden die letzten acht Ziffern)
+oder gleicher Nachname bei gleicher Firma.
+
+**Rückseite.** Nachträglich ein zweites Bild zur Karte aufnehmen. Es wird
+ausgelesen, füllt aber nur Felder, die die Vorderseite offen gelassen hat –
+dort steht oft nur die Mobilnummer.
+
+**Übersicht.** Alle Karten mit Volltextsuche über Name, Firma, Anlass, Ort und
+Notiz. Filter für „nicht exportiert“, „unvollständig“ und „mit Erinnerung“.
+
+**Export und Teilen.** *In Kontakte speichern* liefert eine vCard 3.0, die iOS
+direkt in die Kontakte-App übernimmt. *Als vCard teilen* geht über das
+System-Teilenblatt – per AirDrop, Mail oder Nachricht, ohne Umweg über den
+Download. Bewusst einzeln: ein Sammelexport schiebt zwanzig Kontakte ungeprüft
+ins Adressbuch.
 
 **Notizen und Erinnerungen.** Freitext pro Karte. Erinnerungen mit Termin gehen
 als Mail raus; verpasste Termine holt der Scheduler beim nächsten Start nach.
+Schnellwahl für die üblichen Abstände, damit das Datumsfeld selten gebraucht
+wird.
 
 ## Stack
 
@@ -109,6 +125,7 @@ app/        FastAPI-Anwendung
   segment.py    OpenCV-Pipeline: Karten finden und entzerren
   extract.py    Vision-Modell, strukturiertes JSON
   imaging.py    EXIF-Auswertung, Bildkonvertierung
+  duplicates.py Ähnliche Karten finden
   vcard.py      vCard 3.0
   reminders.py  Scheduler für die Erinnerungsmails
 static/     PWA: HTML, CSS, JavaScript, Service Worker
diff --git a/app/db.py b/app/db.py
index fa068e7..32cdcec 100644
--- a/app/db.py
+++ b/app/db.py
@@ -15,7 +15,9 @@ CREATE TABLE IF NOT EXISTS cards (
     captured_at     TEXT,
     batch_id        TEXT,
     image_file      TEXT,
+    back_image_file TEXT,
     source          TEXT NOT NULL DEFAULT 'batch',
+    occasion        TEXT,
     full_name       TEXT,
     first_name      TEXT,
     last_name       TEXT,
@@ -71,10 +73,27 @@ def connect() -> sqlite3.Connection:
         _conn.execute("PRAGMA journal_mode=WAL")
         _conn.execute("PRAGMA foreign_keys=ON")
         _conn.executescript(SCHEMA)
+        _migrate(_conn)
         _conn.commit()
     return _conn
 
 
+# Spalten, die nach dem ersten Deploy dazugekommen sind. CREATE TABLE IF NOT
+# EXISTS ruehrt eine bestehende Tabelle nicht an - ohne das hier liefe die
+# App auf dem Server mit dem alten Schema weiter.
+LATER_COLUMNS = {
+    "back_image_file": "TEXT",
+    "occasion": "TEXT",
+}
+
+
+def _migrate(conn: sqlite3.Connection) -> None:
+    present = {row["name"] for row in conn.execute("PRAGMA table_info(cards)")}
+    for name, kind in LATER_COLUMNS.items():
+        if name not in present:
+            conn.execute(f"ALTER TABLE cards ADD COLUMN {name} {kind}")
+
+
 def query(sql: str, params: Iterable[Any] = ()) -> list[sqlite3.Row]:
     with _lock:
         return connect().execute(sql, tuple(params)).fetchall()
diff --git a/app/duplicates.py b/app/duplicates.py
new file mode 100644
index 0000000..4586392
--- /dev/null
+++ b/app/duplicates.py
@@ -0,0 +1,55 @@
+"""Karten finden, die dieselbe Person meinen.
+
+Auf Messen trifft man Leute wieder, und dieselbe Karte landet ein zweites Mal
+im Stapel. Verglichen wird nicht der ganze Datensatz, sondern das, was eine
+Person eindeutig macht - in dieser Reihenfolge, weil die Aussagekraft faellt.
+"""
+from . import db
+
+
+def _phone_key(value) -> str:
+    """Nur die letzten acht Ziffern. Damit passen +49 511 123456,
+    0049511123456 und 0511/123456 aufeinander."""
+    digits = "".join(character for character in (value or "") if character.isdigit())
+    return digits[-8:] if len(digits) >= 8 else ""
+
+
+def _phone_keys(row) -> set:
+    return {_phone_key(row["phone"]), _phone_key(row["mobile"])} - {""}
+
+
+def _clean(value) -> str:
+    return (value or "").strip().lower()
+
+
+def _match(card, other) -> str:
+    email = _clean(card["email"])
+    if email and _clean(other["email"]) == email:
+        return "gleiche E-Mail"
+    if _phone_keys(card) & _phone_keys(other):
+        return "gleiche Telefonnummer"
+    last_name, company = _clean(card["last_name"]), _clean(card["company"])
+    if last_name and company:
+        if _clean(other["last_name"]) == last_name and _clean(other["company"]) == company:
+            return "gleicher Name und dieselbe Firma"
+    return ""
+
+
+def find(card) -> list:
+    """Aehnliche Karten, neueste zuerst."""
+    others = db.query(
+        """
+        SELECT id, full_name, first_name, last_name, company, email, phone, mobile,
+               occasion, captured_at, created_at
+        FROM cards
+        WHERE id <> ? AND extract_status <> 'offen'
+        ORDER BY COALESCE(captured_at, created_at) DESC
+        """,
+        (card["id"],),
+    )
+    hits = []
+    for other in others:
+        reason = _match(card, other)
+        if reason:
+            hits.append({**dict(other), "reason": reason})
+    return hits
diff --git a/app/main.py b/app/main.py
index 8d9a956..cd5f561 100644
--- a/app/main.py
+++ b/app/main.py
@@ -10,7 +10,10 @@ from fastapi import Depends, FastAPI, Form, HTTPException, Request, Response, Up
 from fastapi.responses import FileResponse, JSONResponse, PlainTextResponse
 from fastapi.staticfiles import StaticFiles
 
-from . import config, db, extract, geocode, imaging, reminders, security, segment, vcard
+from . import (
+    config, db, duplicates, extract, geocode, imaging, reminders, security,
+    segment, vcard,
+)
 
 logging.basicConfig(level=logging.INFO, format="%(asctime)s %(levelname)s %(name)s %(message)s")
 log = logging.getLogger("bcs")
@@ -21,7 +24,7 @@ MAX_UPLOAD_BYTES = 30 * 1024 * 1024
 EDITABLE = [
     "full_name", "first_name", "last_name", "job_title", "company", "department",
     "email", "phone", "mobile", "fax", "website",
-    "street", "postal_code", "city", "country", "notes",
+    "street", "postal_code", "city", "country", "notes", "occasion",
 ]
 
 
@@ -59,6 +62,9 @@ def now_iso() -> str:
 def card_dict(row) -> dict:
     card = dict(row)
     card["image_url"] = f"/api/cards/{card['id']}/image" if card.get("image_file") else None
+    card["back_image_url"] = (
+        f"/api/cards/{card['id']}/image?side=back" if card.get("back_image_file") else None
+    )
     card["has_contact"] = any(
         card.get(f) for f in ("full_name", "company", "email", "phone", "mobile")
     )
@@ -129,18 +135,19 @@ def _process_photo(raw: bytes) -> tuple:
 _reading: set = set()
 
 
-def start_reading(card_ids: list) -> None:
-    task = asyncio.create_task(_read_cards(card_ids))
+def start_reading(card_ids: list, side: str = "front") -> None:
+    task = asyncio.create_task(_read_cards(card_ids, side))
     _reading.add(task)
     task.add_done_callback(_reading.discard)
 
 
-async def _read_cards(card_ids: list) -> None:
+async def _read_cards(card_ids: list, side: str = "front") -> None:
     """Das Auslesen laeuft nach der Antwort weiter - der Nutzer sieht seine
     Karten sofort, die Felder tropfen nach."""
+    column = "back_image_file" if side == "back" else "image_file"
     rows = [db.query_one("SELECT * FROM cards WHERE id = ?", (i,)) for i in card_ids]
-    rows = [row for row in rows if row is not None]
-    images = [(config.IMAGE_DIR / row["image_file"]).read_bytes() for row in rows]
+    rows = [row for row in rows if row is not None and row[column]]
+    images = [(config.IMAGE_DIR / row[column]).read_bytes() for row in rows]
 
     results = await extract.extract_all(images)
 
@@ -149,7 +156,7 @@ async def _read_cards(card_ids: list) -> None:
         if rotation:
             # Die Lage der Karte auf dem Tisch ist geometrisch nicht
             # bestimmbar - das Modell sagt uns, wie herum sie gehoert.
-            path = config.IMAGE_DIR / row["image_file"]
+            path = config.IMAGE_DIR / row[column]
             path.write_bytes(
                 await asyncio.to_thread(imaging.rotate_jpeg, path.read_bytes(), rotation)
             )
@@ -176,6 +183,7 @@ async def scan(
     file: UploadFile,
     lat: float = Form(None),
     lon: float = Form(None),
+    occasion: str = Form(""),
 ) -> JSONResponse:
     raw = await file.read()
     if not raw:
@@ -219,6 +227,7 @@ async def scan(
             "lon": meta["lon"],
             "place": place,
             "geo_source": geo_source,
+            "occasion": occasion.strip() or None,
             "extract_status": "offen",
         }
         names = ", ".join(columns)
@@ -247,7 +256,7 @@ def list_cards(q: str = "", filter: str = "alle") -> dict:
         needle = f"%{q.strip()}%"
         searchable = [
             "full_name", "company", "job_title", "email", "phone", "mobile",
-            "website", "city", "place", "notes", "department", "street",
+            "website", "city", "place", "notes", "department", "street", "occasion",
         ]
         where.append("(" + " OR ".join(f"{c} LIKE ?" for c in searchable) + ")")
         params += [needle] * len(searchable)
@@ -305,6 +314,7 @@ def get_card(card_id: str) -> dict:
             "SELECT * FROM reminders WHERE card_id = ? ORDER BY due_at", (card_id,)
         )
     ]
+    card["duplicates"] = duplicates.find(card)
     return card
 
 
@@ -327,21 +337,52 @@ async def update_card(card_id: str, request: Request) -> dict:
 @app.delete("/api/cards/{card_id}", dependencies=[auth])
 def delete_card(card_id: str) -> dict:
     row = _card_or_404(card_id)
-    if row["image_file"]:
-        (config.IMAGE_DIR / row["image_file"]).unlink(missing_ok=True)
+    for name in (row["image_file"], row["back_image_file"]):
+        if name:
+            (config.IMAGE_DIR / name).unlink(missing_ok=True)
     db.execute("DELETE FROM cards WHERE id = ?", (card_id,))
     return {"ok": True}
 
 
 @app.get("/api/cards/{card_id}/image", dependencies=[auth])
-def card_image(card_id: str) -> FileResponse:
+def card_image(card_id: str, side: str = "front") -> FileResponse:
     row = _card_or_404(card_id)
-    path = config.IMAGE_DIR / (row["image_file"] or "")
-    if not row["image_file"] or not path.exists():
+    name = row["back_image_file"] if side == "back" else row["image_file"]
+    path = config.IMAGE_DIR / (name or "")
+    if not name or not path.exists():
         raise HTTPException(status_code=404, detail="Kein Bild gespeichert")
     return FileResponse(path, media_type="image/jpeg")
 
 
+@app.post("/api/cards/{card_id}/back", dependencies=[auth])
+async def add_back(card_id: str, file: UploadFile) -> dict:
+    """Rueckseite nachtragen. Sie wird ausgelesen, fuellt aber nur Felder, die
+    die Vorderseite offen gelassen hat - dort steht oft nur die Mobilnummer."""
+    row = _card_or_404(card_id)
+    raw = await file.read()
+    if not raw:
+        raise HTTPException(status_code=400, detail="Leere Datei")
+    if len(raw) > MAX_UPLOAD_BYTES:
+        raise HTTPException(status_code=413, detail="Foto ist groesser als 30 MB")
+
+    try:
+        _, encoded, _ = await asyncio.to_thread(_process_photo, raw)
+    except Exception as exc:
+        log.exception("Rueckseite konnte nicht verarbeitet werden")
+        raise HTTPException(status_code=400, detail=f"Bild nicht lesbar: {exc}") from exc
+    if not encoded:
+        raise HTTPException(status_code=400, detail="Keine Karte im Bild gefunden")
+
+    name = f"{card_id}-back.jpg"
+    (config.IMAGE_DIR / name).write_bytes(encoded[0])
+    db.execute(
+        "UPDATE cards SET back_image_file = ?, extract_status = 'offen' WHERE id = ?",
+        (name, card_id),
+    )
+    start_reading([card_id], side="back")
+    return card_dict(_card_or_404(card_id))
+
+
 # ---------------------------------------------------------------------------- Export
 
 @app.get("/vcf/{card_id}", dependencies=[auth])
diff --git a/static/app.js b/static/app.js
index c475ff4..a20fb80 100644
--- a/static/app.js
+++ b/static/app.js
@@ -18,6 +18,7 @@
     postal_code: "PLZ",
     city: "Ort",
     country: "Land",
+    occasion: "Anlass",
   };
   const FIELD_ORDER = Object.keys(FIELD_LABELS);
 
@@ -27,7 +28,7 @@
     query: "",
     filter: "alle",
     cards: [],
-    stats: { total: 0, offen: 0, erinnerungen: 0 },
+    stats: { total: 0, offen: 0, erinnerungen: 0, laeuft: 0 },
     editing: false,
   };
 
@@ -44,6 +45,15 @@
       "&": "&amp;", "<": "&lt;", ">": "&gt;", '"': "&quot;", "'": "&#39;",
     })[c]);
 
+  const store = {
+    get(key) {
+      try { return localStorage.getItem(key) || ""; } catch (_) { return ""; }
+    },
+    set(key, value) {
+      try { localStorage.setItem(key, value); } catch (_) { /* privater Modus */ }
+    },
+  };
+
   // ------------------------------------------------------------------ Helfer
 
   function toast(message) {
@@ -55,7 +65,7 @@
   }
 
   function busy(on, text) {
-    $("busy-text").textContent = text || "Karten werden gelesen";
+    $("busy-text").textContent = text || "Karten werden freigestellt";
     $("busy-overlay").hidden = !on;
   }
 
@@ -98,6 +108,9 @@
     card.company ||
     "Ohne Namen";
 
+  const subtitle = (card) =>
+    [card.job_title, card.company].filter(Boolean).join(" · ") || "Keine Firma erkannt";
+
   /** Position des Browsers als Rückfallebene. Die EXIF-Daten des Fotos sind
    *  genauer, deshalb blockiert das hier nichts und scheitert leise. */
   function browserPosition() {
@@ -111,24 +124,31 @@
     });
   }
 
-  /** Zustand einer Karte als abgestufte Pillen: schwarz, was erledigt ist,
-   *  grau umrandet, was noch offen oder auffaellig ist. */
+  /** Zustand einer Karte als Pillen. Ob sie schon exportiert wurde, steht
+   *  bewusst nicht dabei - dafür gibt es den Filter. */
   function cardTags(card) {
     const tags = [];
-    if (card.place) tags.push(["", card.place]);
-    if (card.extract_status === "offen") {
-      tags.push(["pill-solid", "wird gelesen"]);
-    } else {
-      tags.push(
-        card.exported_at ? ["pill-solid", "exportiert"] : ["", "nicht exportiert"]
-      );
-      if (card.extract_status === "fehler") tags.push(["", "Lesefehler"]);
-    }
+    if (card.occasion) tags.push(["pill-solid", card.occasion]);
+    else if (card.place) tags.push(["", card.place]);
+    if (card.extract_status === "offen") tags.push(["", "wird gelesen"]);
+    if (card.extract_status === "fehler") tags.push(["", "Lesefehler"]);
     return tags
       .map(([extra, text]) => `<span class="pill ${extra}">${esc(text)}</span>`)
       .join("");
   }
 
+  function cardRow(card) {
+    return `
+      <button class="row" data-card="${esc(card.id)}">
+        <span class="row-head">
+          <span class="row-title">${esc(displayName(card))}</span>
+          <span class="row-meta">${esc(formatDate(card.captured_at || card.created_at))}</span>
+        </span>
+        <span class="row-sub">${esc(subtitle(card))}</span>
+        <span class="row-tags">${cardTags(card)}</span>
+      </button>`;
+  }
+
   // ----------------------------------------------------------------- Routing
 
   function go(route, cardId) {
@@ -143,11 +163,13 @@
 
     Object.entries(screens).forEach(([name, node]) => { node.hidden = name !== route; });
     document.querySelectorAll(".tab").forEach((tab) => {
-      const active = tab.dataset.route === route || (route === "karte" && tab.dataset.route === "karten");
+      const active =
+        tab.dataset.route === route || (route === "karte" && tab.dataset.route === "karten");
       tab.setAttribute("aria-selected", active ? "true" : "false");
     });
     window.scrollTo(0, 0);
 
+    if (route === "scan") loadRecent();
     if (route === "karten") loadCards();
     if (route === "karte") loadCard(state.cardId);
     if (route === "erinnerungen") loadReminders();
@@ -160,19 +182,18 @@
     busy(true, "Karten werden freigestellt");
     const body = new FormData();
     body.append("file", file);
+    body.append("occasion", $("occasion-input").value.trim());
     const coords = await browserPosition();
     if (coords) {
       body.append("lat", coords.latitude);
       body.append("lon", coords.longitude);
     }
-    busy(true, "Karten werden gelesen");
     try {
       const result = await api("/api/scan", { method: "POST", body });
       renderScanResult(result);
       await refreshStats();
-      toast(
-        `${result.count} Karte${result.count === 1 ? "" : "n"} erfasst, wird gelesen`
-      );
+      loadRecent();
+      toast(`${result.count} Karte${result.count === 1 ? "" : "n"} erfasst, wird gelesen`);
     } catch (error) {
       toast(error.message);
     } finally {
@@ -181,31 +202,43 @@
   }
 
   function renderScanResult(result) {
-    const rows = result.cards
-      .map(
-        (card) => `
-        <button class="row" data-card="${esc(card.id)}">
-          <span class="row-head">
-            <span class="row-title">${esc(displayName(card))}</span>
-            <span class="row-meta">wird gelesen</span>
-          </span>
-          <span class="row-sub">${esc(card.company || card.email || "Zuschnitt gespeichert")}</span>
-        </button>`
-      )
-      .join("");
-
     $("scan-result").innerHTML = `
       <div class="section-label"><span class="label">Ergebnis</span></div>
-      <div class="strip" style="border-top:3px solid #000">
-        <span class="label">Gefundene Karten</span>
-        <span class="display d-lg mono-num">${result.count}</span>
+      <div class="strip">
+        <span class="label">${result.count} Karte${result.count === 1 ? "" : "n"} gefunden</span>
+        <span class="pill">wird gelesen</span>
       </div>
       ${result.fallback
         ? `<p class="hint" style="margin-top:10px">Kein Kartenrechteck erkannt – das ganze Foto
            wurde als eine Karte behandelt. Für einen Stapel hilft ein dunkler, einfarbiger
            Untergrund mit Abstand zwischen den Karten.</p>`
         : ""}
-      <div class="rows" style="margin-top:14px">${rows}</div>`;
+      <div class="rows" style="margin-top:12px">
+        ${result.cards.map(cardRow).join("")}
+      </div>`;
+  }
+
+  async function loadRecent() {
+    try {
+      const data = await api("/api/cards?filter=alle");
+      state.stats = data.stats;
+      updateCounters();
+      const recent = data.cards.slice(0, 3);
+      $("recent-list").innerHTML = recent.length
+        ? `<div class="rows">${recent.map(cardRow).join("")}</div>
+           ${data.cards.length > 3
+             ? `<button class="btn btn-quiet" data-goto="karten" style="margin-top:12px">
+                  Alle ${data.stats.total} Karten <span class="arrow">→</span>
+                </button>`
+             : ""}`
+        : `<div class="empty">
+             <p class="label">Noch nichts erfasst</p>
+             <p class="hint" style="margin:8px 0 0">Mach oben ein Foto – der Rest passiert von allein.</p>
+           </div>`;
+      schedulePoll();
+    } catch (error) {
+      toast(error.message);
+    }
   }
 
   // ------------------------------------------------------------- Kartenliste
@@ -224,7 +257,7 @@
     }
   }
 
-  /** Das Auslesen laeuft auf dem Server weiter, nachdem der Scan geantwortet
+  /** Das Auslesen läuft auf dem Server weiter, nachdem der Scan geantwortet
    *  hat. Solange noch etwas offen ist, holen wir den Stand nach. */
   function schedulePoll() {
     clearTimeout(schedulePoll.timer);
@@ -232,6 +265,7 @@
     schedulePoll.timer = setTimeout(() => {
       if (state.route === "karten") loadCards();
       else if (state.route === "karte") loadCard(state.cardId);
+      else if (state.route === "scan") loadRecent();
       else refreshStats();
     }, 3000);
   }
@@ -254,23 +288,7 @@
         <span class="label">${state.cards.length} Karte${state.cards.length === 1 ? "" : "n"}</span>
         ${state.stats.laeuft ? `<span class="pill">${state.stats.laeuft} werden gelesen</span>` : ""}
       </div>
-      <div class="rows">
-        ${state.cards
-          .map(
-            (card) => `
-          <button class="row" data-card="${esc(card.id)}">
-            <span class="row-head">
-              <span class="row-title">${esc(displayName(card))}</span>
-              <span class="row-meta">${esc(formatDate(card.captured_at || card.created_at))}</span>
-            </span>
-            <span class="row-sub">
-              ${esc([card.job_title, card.company].filter(Boolean).join(" · ") || "Keine Firma erkannt")}
-            </span>
-            <span class="row-tags">${cardTags(card)}</span>
-          </button>`
-          )
-          .join("")}
-      </div>`;
+      <div class="rows">${state.cards.map(cardRow).join("")}</div>`;
   }
 
   // ----------------------------------------------------------- Kartendetail
@@ -280,7 +298,7 @@
       const card = await api(`/api/cards/${cardId}`);
       renderCard(card);
       if (card.extract_status === "offen") {
-        state.stats = { ...state.stats, laeuft: 1 };
+        state.stats = { ...state.stats, laeuft: Math.max(1, state.stats.laeuft) };
         schedulePoll();
       }
     } catch (error) {
@@ -290,10 +308,7 @@
 
   function dataTable(card) {
     const rows = FIELD_ORDER.filter((field) => card[field])
-      .map(
-        (field) =>
-          `<tr><th>${FIELD_LABELS[field]}</th><td>${esc(card[field])}</td></tr>`
-      )
+      .map((field) => `<tr><th>${FIELD_LABELS[field]}</th><td>${esc(card[field])}</td></tr>`)
       .join("");
     return rows
       ? `<table class="data">${rows}</table>`
@@ -310,18 +325,47 @@
     ).join("")}</div>`;
   }
 
-  function renderCard(card) {
-    const meta = [];
-    if (card.place) meta.push(esc(card.place));
-    if (card.lat != null) meta.push(`${card.lat.toFixed(4)}, ${card.lon.toFixed(4)}`);
+  function duplicateBlock(card) {
+    if (!card.duplicates || !card.duplicates.length) return "";
+    return `
+      <div class="section-label"><span class="label">Schon einmal erfasst?</span></div>
+      <div class="rows">
+        ${card.duplicates
+          .map(
+            (other) => `
+          <button class="row" data-card="${esc(other.id)}">
+            <span class="row-head">
+              <span class="row-title">${esc(displayName(other))}</span>
+              <span class="row-meta">${esc(formatDate(other.captured_at || other.created_at))}</span>
+            </span>
+            <span class="row-sub">${esc(other.reason)}${other.occasion ? " · " + esc(other.occasion) : ""}</span>
+          </button>`
+          )
+          .join("")}
+      </div>`;
+  }
 
+  const QUICK_DATES = [
+    ["In 3 Tagen", 3],
+    ["In 1 Woche", 7],
+    ["In 2 Wochen", 14],
+    ["In 1 Monat", 30],
+  ];
+
+  function localInputValue(date) {
+    const pad = (n) => String(n).padStart(2, "0");
+    return `${date.getFullYear()}-${pad(date.getMonth() + 1)}-${pad(date.getDate())}` +
+      `T${pad(date.getHours())}:${pad(date.getMinutes())}`;
+  }
+
+  function renderCard(card) {
     const reminders = card.reminders.length
       ? `<div class="rows">${card.reminders
           .map(
             (reminder) => `
           <div class="row" style="cursor:default">
             <span class="row-head">
-              <span class="row-title" style="font-size:14px">${esc(reminder.text)}</span>
+              <span class="row-title" style="font-size:15px">${esc(reminder.text)}</span>
               <button class="badge" data-delete-reminder="${esc(reminder.id)}">Löschen</button>
             </span>
             <span class="row-sub">
@@ -335,14 +379,12 @@
       : `<p class="hint">Keine Erinnerung gesetzt.</p>`;
 
     screens.karte.innerHTML = `
-      <button class="chip" data-back>← Zurück</button>
+      <button class="chip" data-back>← Karten</button>
 
       <div class="block-invert">
-        <p class="label">${card.source === "stapel" ? "Aus Stapelscan" : "Einzelscan"}</p>
+        <p class="label">${esc(card.occasion || (card.source === "stapel" ? "Aus Stapelscan" : "Einzelscan"))}</p>
         <h1 class="display d-lg" style="margin-top:8px">${esc(displayName(card))}</h1>
-        <p class="muted" style="margin:6px 0 0">
-          ${esc([card.job_title, card.company].filter(Boolean).join(" · ") || "Keine Firma erkannt")}
-        </p>
+        <p class="muted" style="margin:6px 0 0">${esc(subtitle(card))}</p>
         <div class="figures">
           <span class="figure">
             <span class="label">Erfasst</span>
@@ -350,18 +392,27 @@
           </span>
           <span class="figure">
             <span class="label">Ort</span>
-            <span class="display d-md">${meta.length ? esc(meta[0]) : "Unbekannt"}</span>
+            <span class="display d-md">${esc(card.place || "Unbekannt")}</span>
           </span>
         </div>
       </div>
 
       ${card.image_url
-        ? `<img class="card-image" src="${esc(card.image_url)}" alt="Visitenkarte">`
+        ? `<img class="card-image" src="${esc(card.image_url)}" alt="Vorderseite">`
         : ""}
+      ${card.back_image_url
+        ? `<img class="card-image" src="${esc(card.back_image_url)}" alt="Rückseite">`
+        : `<label class="btn btn-quiet" for="input-back">
+             Rückseite hinzufügen <span class="arrow">+</span>
+             <input id="input-back" type="file" accept="image/*" capture="environment" hidden>
+           </label>`}
 
       <a class="btn btn-primary" href="/vcf/${esc(card.id)}" download>
         In Kontakte speichern <span class="arrow">→</span>
       </a>
+      <button class="btn" data-share="${esc(card.id)}">
+        Als vCard teilen <span class="arrow">↗</span>
+      </button>
 
       ${card.extract_status === "offen"
         ? `<p class="hint">Die Karte wird gerade ausgelesen – die Felder erscheinen gleich.</p>`
@@ -370,9 +421,9 @@
         ? `<p class="hint">Lesefehler: ${esc(card.extract_error || "unbekannt")}</p>`
         : ""}
 
-      <div class="section-label">
-        <span class="label">Daten</span>
-      </div>
+      ${duplicateBlock(card)}
+
+      <div class="section-label"><span class="label">Daten</span></div>
       <button class="chip" data-toggle-edit style="margin-bottom:10px">
         ${state.editing ? "Fertig" : "Bearbeiten"}
       </button>
@@ -390,7 +441,12 @@
           <span class="label">Text</span>
           <input name="text" placeholder="Angebot nachfassen" required>
         </label>
-        <label class="field">
+        <div class="chips" style="margin-top:12px">
+          ${QUICK_DATES.map(
+            ([text, days]) => `<button class="chip" type="button" data-quick="${days}">${text}</button>`
+          ).join("")}
+        </div>
+        <label class="field" style="margin-top:12px">
           <span class="label">Termin</span>
           <input name="due" type="datetime-local" required>
         </label>
@@ -417,9 +473,39 @@
       });
     });
 
-    $("reminder-form").addEventListener("submit", async (event) => {
+    const backInput = $("input-back");
+    if (backInput) {
+      backInput.addEventListener("change", async (event) => {
+        const file = event.target.files[0];
+        event.target.value = "";
+        if (!file) return;
+        busy(true, "Rückseite wird gelesen");
+        try {
+          const body = new FormData();
+          body.append("file", file);
+          await api(`/api/cards/${card.id}/back`, { method: "POST", body });
+          toast("Rückseite hinzugefügt");
+          loadCard(card.id);
+        } catch (error) {
+          toast(error.message);
+        } finally {
+          busy(false);
+        }
+      });
+    }
+
+    const form = $("reminder-form");
+    form.querySelectorAll("[data-quick]").forEach((button) => {
+      button.addEventListener("click", () => {
+        const date = new Date();
+        date.setDate(date.getDate() + Number(button.dataset.quick));
+        date.setHours(9, 0, 0, 0);
+        form.elements.due.value = localInputValue(date);
+      });
+    });
+
+    form.addEventListener("submit", async (event) => {
       event.preventDefault();
-      const form = event.currentTarget;
       const due = form.elements.due.value;
       if (!due) return;
       try {
@@ -440,6 +526,34 @@
     });
   }
 
+  /** Teilen über das System-Teilenblatt. Damit landet die vCard per AirDrop,
+   *  Mail oder Nachricht beim Gegenüber, ohne Umweg über den Download. */
+  async function shareCard(cardId) {
+    try {
+      const response = await fetch(`/vcf/${cardId}`, { credentials: "same-origin" });
+      if (!response.ok) throw new Error("vCard konnte nicht geladen werden");
+      const disposition = response.headers.get("content-disposition") || "";
+      const match = disposition.match(/filename="([^"]+)"/);
+      const blob = await response.blob();
+      const file = new File([blob], match ? match[1] : "kontakt.vcf", {
+        type: "text/vcard",
+      });
+      if (navigator.canShare && navigator.canShare({ files: [file] })) {
+        await navigator.share({ files: [file] });
+        return;
+      }
+      // Kein Teilenblatt (Desktop, ältere Browser): dann eben herunterladen.
+      const url = URL.createObjectURL(blob);
+      const link = document.createElement("a");
+      link.href = url;
+      link.download = file.name;
+      link.click();
+      URL.revokeObjectURL(url);
+    } catch (error) {
+      if (error.name !== "AbortError") toast(error.message);
+    }
+  }
+
   // ------------------------------------------------------------ Erinnerungen
 
   async function loadReminders() {
@@ -473,11 +587,15 @@
 
   // -------------------------------------------------------------- Zähler
 
+  function badge(id, value) {
+    const node = $(id);
+    node.textContent = value;
+    node.hidden = !value;
+  }
+
   function updateCounters() {
-    $("figure-total").textContent = state.stats.total;
-    $("figure-open").textContent = state.stats.offen;
-    $("tab-count-cards").textContent = state.stats.total;
-    $("tab-count-reminders").textContent = state.stats.erinnerungen;
+    badge("tab-count-cards", state.stats.total);
+    badge("tab-count-reminders", state.stats.erinnerungen);
   }
 
   async function refreshStats() {
@@ -492,9 +610,15 @@
   // ------------------------------------------------------------- Ereignisse
 
   document.addEventListener("click", (event) => {
+    const shareButton = event.target.closest("[data-share]");
+    if (shareButton) return shareCard(shareButton.dataset.share);
+
     const cardButton = event.target.closest("[data-card]");
     if (cardButton) return go("karte", cardButton.dataset.card);
 
+    const goto = event.target.closest("[data-goto]");
+    if (goto) return go(goto.dataset.goto);
+
     if (event.target.closest("[data-back]")) {
       state.editing = false;
       return go("karten");
@@ -547,6 +671,12 @@
     loadCards();
   });
 
+  // Der Anlass gilt für eine ganze Messe, nicht für einen Scan.
+  $("occasion-input").value = store.get("occasion");
+  $("occasion-input").addEventListener("change", (event) => {
+    store.set("occasion", event.target.value.trim());
+  });
+
   ["input-camera", "input-library"].forEach((id) => {
     $(id).addEventListener("change", (event) => {
       const file = event.target.files[0];
@@ -560,10 +690,10 @@
     const body = new FormData();
     body.append("password", $("login-password").value);
     try {
-      await fetch("/api/login", { method: "POST", body, credentials: "same-origin" })
-        .then((response) => {
-          if (!response.ok) throw new Error("Passwort stimmt nicht");
-        });
+      const response = await fetch("/api/login", {
+        method: "POST", body, credentials: "same-origin",
+      });
+      if (!response.ok) throw new Error("Passwort stimmt nicht");
       $("login-overlay").hidden = true;
       $("login-error").hidden = true;
       boot();
@@ -593,7 +723,6 @@
       if (!session.extraction_available) {
         toast("Kein API-Schlüssel gesetzt – Karten werden nur zugeschnitten.");
       }
-      await refreshStats();
       applyRoute();
     } catch (error) {
       toast("Server nicht erreichbar");
diff --git a/static/index.html b/static/index.html
index 2f1f569..51725a9 100644
--- a/static/index.html
+++ b/static/index.html
@@ -34,46 +34,44 @@
   <main>
     <!-- ------------------------------------------------------------- Scan -->
     <section class="screen stack" id="screen-scan">
-      <div class="block-invert">
-        <p class="label">Stapel oder Einzelkarte</p>
-        <h1 class="display d-xl" style="margin-top:8px">Karten<br>erfassen</h1>
-        <p class="muted" style="margin:12px 0 0">
-          Karten nebeneinander auf einen dunklen, einfarbigen Untergrund legen,
-          Handy parallel darüber halten. Ein Foto genügt für den ganzen Tisch.
-        </p>
-        <div class="figures">
-          <span class="figure">
-            <span class="label">Erfasst</span>
-            <span class="display d-lg mono-num" id="figure-total">0</span>
-          </span>
-          <span class="figure">
-            <span class="label">Nicht exportiert</span>
-            <span class="display d-lg mono-num" id="figure-open">0</span>
-          </span>
-        </div>
-      </div>
+      <label class="field">
+        <span class="label">Anlass · gilt für die nächsten Scans</span>
+        <input id="occasion-input" placeholder="z. B. Hannover Messe 2026"
+               autocomplete="off" enterkeyhint="done">
+      </label>
 
-      <label class="btn btn-primary" for="input-camera">
-        Foto aufnehmen <span class="arrow">→</span>
+      <label class="action" for="input-camera">
+        <span class="action-icon" aria-hidden="true">
+          <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.8">
+            <path d="M3 7h3l1.5-2h9L18 7h3v12H3z"></path>
+            <circle cx="12" cy="13" r="3.6"></circle>
+          </svg>
+        </span>
+        <span class="action-body">
+          <span class="display d-lg">Foto aufnehmen</span>
+          <span class="action-hint">
+            Karten nebeneinander auf einen dunklen Untergrund legen.
+            Ein Foto reicht für den ganzen Tisch.
+          </span>
+        </span>
         <input id="input-camera" type="file" accept="image/*" capture="environment" hidden>
       </label>
+
       <label class="btn btn-quiet" for="input-library">
         Aus Fotos wählen <span class="arrow">↗</span>
         <input id="input-library" type="file" accept="image/*" hidden>
       </label>
 
-      <p class="hint">
-        Die Kamera liefert die volle Auflösung – bei zwanzig Karten auf einem Foto
-        ist das der Unterschied zwischen lesbar und nicht lesbar.
-      </p>
-
       <div id="scan-result"></div>
+
+      <div class="section-label"><span class="label">Zuletzt erfasst</span></div>
+      <div id="recent-list"></div>
     </section>
 
     <!-- ------------------------------------------------------------ Karten -->
     <section class="screen stack" id="screen-cards" hidden>
       <div class="search">
-        <input id="search-input" type="search" placeholder="Name, Firma, Ort, Notiz …"
+        <input id="search-input" type="search" placeholder="Name, Firma, Anlass, Notiz …"
                autocomplete="off" enterkeyhint="search">
         <button id="search-clear" type="button" aria-label="Suche leeren">×</button>
       </div>
@@ -97,12 +95,34 @@
   </main>
 
   <nav class="tabs" role="tablist">
-    <button class="tab" role="tab" data-route="scan" aria-selected="true">Scan</button>
+    <button class="tab" role="tab" data-route="scan" aria-selected="true">
+      <span class="tab-icon" aria-hidden="true">
+        <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.9">
+          <path d="M3 7h3l1.5-2h9L18 7h3v12H3z"></path>
+          <circle cx="12" cy="13" r="3.4"></circle>
+        </svg>
+      </span>
+      <span class="tab-label">Scannen</span>
+    </button>
     <button class="tab" role="tab" data-route="karten" aria-selected="false">
-      <span class="count mono-num" id="tab-count-cards">0</span>Karten
+      <span class="tab-icon" aria-hidden="true">
+        <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.9">
+          <rect x="3" y="6" width="18" height="13"></rect>
+          <path d="M7 11h5M7 15h8"></path>
+        </svg>
+      </span>
+      <span class="tab-label">Karten</span>
+      <span class="tab-badge mono-num" id="tab-count-cards" hidden>0</span>
     </button>
     <button class="tab" role="tab" data-route="erinnerungen" aria-selected="false">
-      <span class="count mono-num" id="tab-count-reminders">0</span>Termine
+      <span class="tab-icon" aria-hidden="true">
+        <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.9">
+          <circle cx="12" cy="12" r="8.5"></circle>
+          <path d="M12 7v5.2l3.4 2"></path>
+        </svg>
+      </span>
+      <span class="tab-label">Termine</span>
+      <span class="tab-badge mono-num" id="tab-count-reminders" hidden>0</span>
     </button>
   </nav>
 </div>
@@ -125,7 +145,7 @@
 <div class="overlay" id="busy-overlay" hidden>
   <div class="block-invert stack" style="text-align:center">
     <div class="spinner" style="margin:0 auto"></div>
-    <p class="label" id="busy-text">Karten werden gelesen</p>
+    <p class="label" id="busy-text">Karten werden freigestellt</p>
   </div>
 </div>
 
diff --git a/static/style.css b/static/style.css
index b1d99f7..c51f3a5 100644
--- a/static/style.css
+++ b/static/style.css
@@ -27,7 +27,7 @@
 html, body {
   margin: 0;
   padding: 0;
-  background: var(--page);
+  background: var(--bg);
   color: var(--ink);
   font-family: var(--sans);
   font-size: 15px;
@@ -35,7 +35,17 @@ html, body {
   -webkit-text-size-adjust: 100%;
 }
 
-body { overflow-x: hidden; }
+body {
+  overflow-x: hidden;
+  overscroll-behavior-y: none;
+  -webkit-tap-highlight-color: transparent;
+}
+
+/* Bedienelemente verhalten sich wie in einer App, nicht wie Fliesstext. */
+.btn, .chip, .tab, .row, .badge, .pill, .action, .label, .topbar {
+  -webkit-user-select: none;
+  user-select: none;
+}
 
 button, input, textarea, select {
   font: inherit;
@@ -81,8 +91,6 @@ a { color: inherit; }
   margin: 0 auto;
   min-height: 100vh;
   background: var(--bg);
-  border-left: 1px solid var(--ink);
-  border-right: 1px solid var(--ink);
   display: flex;
   flex-direction: column;
 }
@@ -95,6 +103,7 @@ a { color: inherit; }
   align-items: center;
   gap: 12px;
   padding: 13px var(--pad);
+  padding-top: calc(13px + env(safe-area-inset-top));
   background: var(--bg);
   border-bottom: 3px solid var(--ink);
 }
@@ -117,7 +126,12 @@ a { color: inherit; }
 .topbar .spacer { margin-left: auto; }
 
 main { flex: 1; display: flex; flex-direction: column; }
-.screen { flex: 1; padding: var(--pad) var(--pad) 30px; }
+.screen { flex: 1; padding: var(--pad) var(--pad) 30px; animation: rise 0.18s ease-out; }
+
+@keyframes rise {
+  from { opacity: 0; transform: translateY(7px); }
+  to { opacity: 1; transform: none; }
+}
 .screen[hidden] { display: none; }
 
 .stack > * + * { margin-top: 12px; }
@@ -191,6 +205,7 @@ main { flex: 1; display: flex; flex-direction: column; }
   justify-content: space-between;
   gap: 10px;
   width: 100%;
+  min-height: 54px;
   padding: 16px;
   background: var(--bg);
   border: 2px solid var(--ink);
@@ -203,6 +218,24 @@ main { flex: 1; display: flex; flex-direction: column; }
   text-align: left;
 }
 
+/* Die eine Sache, die man auf der Startseite tut. Grosse Flaeche statt
+   Textzeile - auf dem Telefon zaehlt die Trefferflaeche, nicht die Kante. */
+.action {
+  display: flex;
+  align-items: center;
+  gap: 16px;
+  padding: 22px 18px;
+  background: var(--ink);
+  color: var(--bg);
+  cursor: pointer;
+}
+
+.action:active { background: #1f1f1f; }
+.action-icon { flex: 0 0 42px; color: var(--bg); }
+.action-icon svg { width: 42px; height: 42px; display: block; }
+.action-body { display: flex; flex-direction: column; gap: 7px; }
+.action-hint { font-size: 12.5px; line-height: 1.45; color: #a9a9a9; }
+
 /* Was man hier tun soll. */
 .btn-primary { background: var(--ink); color: var(--bg); border-color: var(--ink); }
 
@@ -274,7 +307,7 @@ main { flex: 1; display: flex; flex-direction: column; }
 
 /* Ungewaehlt zurueckgenommen, damit die Auswahl ueberhaupt auffaellt. */
 .chip {
-  padding: 7px 11px;
+  padding: 9px 12px;
   border: 1px solid var(--rule);
   background: var(--bg);
   color: var(--ink-3);
@@ -402,15 +435,16 @@ main { flex: 1; display: flex; flex-direction: column; }
 }
 
 .tab {
+  position: relative;
   flex: 1;
-  padding: 12px 4px calc(12px + env(safe-area-inset-bottom));
+  padding: 10px 4px calc(10px + env(safe-area-inset-bottom));
   background: var(--bg);
   border: none;
   border-left: 1px solid var(--rule);
   color: var(--ink-3);
   font-size: 10px;
   font-weight: 700;
-  letter-spacing: 0.12em;
+  letter-spacing: 0.1em;
   text-transform: uppercase;
   cursor: pointer;
 }
@@ -418,15 +452,27 @@ main { flex: 1; display: flex; flex-direction: column; }
 .tab:first-child { border-left: none; }
 .tab[aria-selected="true"] { background: var(--ink); color: var(--bg); }
 
-.tab .count {
-  display: block;
-  font-size: 17px;
+.tab-icon { display: block; width: 24px; height: 24px; margin: 0 auto 4px; }
+.tab-icon svg { width: 24px; height: 24px; display: block; }
+.tab-label { display: block; }
+
+.tab-badge {
+  position: absolute;
+  top: 6px;
+  right: 50%;
+  transform: translateX(26px);
+  min-width: 18px;
+  padding: 1px 4px;
+  background: var(--ink);
+  color: var(--bg);
+  border: 1px solid var(--bg);
+  font-size: 10px;
   font-weight: 800;
-  color: var(--ink);
-  margin-bottom: 1px;
+  letter-spacing: 0;
 }
 
-.tab[aria-selected="true"] .count { color: var(--bg); }
+.tab-badge[hidden] { display: none; }
+.tab[aria-selected="true"] .tab-badge { background: var(--bg); color: var(--ink); border-color: var(--ink); }
 
 /* ------------------------------------------------------------------- Zustaende */
 
@@ -484,8 +530,11 @@ main { flex: 1; display: flex; flex-direction: column; }
 
 .toast[hidden] { display: none; }
 
+/* Nur am grossen Bildschirm ein Rahmen - auf dem Telefon fuellt die App
+   den Schirm, wie eine App das tut. */
 @media (min-width: 600px) {
   :root { --pad: 26px; }
+  body { background: var(--page); }
   .app { border: 1px solid var(--ink); margin: 26px auto; min-height: calc(100vh - 52px); }
   .d-xl { font-size: 52px; }
 }
diff --git a/tests/test_api.py b/tests/test_api.py
index 6b362f0..6b8f2cb 100644
--- a/tests/test_api.py
+++ b/tests/test_api.py
@@ -262,3 +262,96 @@ def test_handeintrag_ueberlebt_den_hintergrundlauf(client, monkeypatch):
     card = client.get(f"/api/cards/{card_id}").json()
     assert card["full_name"] == "Von Hand"
     assert card["notes"] == "Messe"
+
+
+def test_anlass_wird_gespeichert_und_ist_durchsuchbar(client):
+    created = client.post(
+        "/api/scan",
+        files={"file": ("tisch.jpg", photo_bytes(2), "image/jpeg")},
+        data={"occasion": "Hannover Messe 2026"},
+    ).json()
+    ids = [c["id"] for c in created["cards"]]
+    warte_bis_gelesen(client, ids)
+
+    assert all(c["occasion"] == "Hannover Messe 2026" for c in created["cards"])
+
+    gefunden = client.get("/api/cards", params={"q": "hannover messe"}).json()["cards"]
+    assert set(ids) <= {c["id"] for c in gefunden}
+
+
+def test_anlass_ist_nachtraeglich_aenderbar(client):
+    card_id = client.post(
+        "/api/scan", files={"file": ("einzel.jpg", photo_bytes(1), "image/jpeg")}
+    ).json()["cards"][0]["id"]
+    warte_bis_gelesen(client, [card_id])
+
+    patched = client.patch(f"/api/cards/{card_id}", json={"occasion": "Kundentermin"})
+
+    assert patched.json()["occasion"] == "Kundentermin"
+
+
+def test_dubletten_stehen_in_der_detailansicht(client):
+    erste = client.post(
+        "/api/scan", files={"file": ("a.jpg", photo_bytes(1), "image/jpeg")}
+    ).json()["cards"][0]["id"]
+    zweite = client.post(
+        "/api/scan", files={"file": ("b.jpg", photo_bytes(1), "image/jpeg")}
+    ).json()["cards"][0]["id"]
+    warte_bis_gelesen(client, [erste, zweite])
+    for card_id in (erste, zweite):
+        client.patch(f"/api/cards/{card_id}", json={"email": "doppelt@firma.de"})
+
+    detail = client.get(f"/api/cards/{zweite}").json()
+
+    assert erste in [d["id"] for d in detail["duplicates"]]
+    assert detail["duplicates"][0]["reason"] == "gleiche E-Mail"
+
+
+def test_rueckseite_nachtragen(client):
+    card_id = client.post(
+        "/api/scan", files={"file": ("vorne.jpg", photo_bytes(1), "image/jpeg")}
+    ).json()["cards"][0]["id"]
+    warte_bis_gelesen(client, [card_id])
+
+    response = client.post(
+        f"/api/cards/{card_id}/back",
+        files={"file": ("hinten.jpg", photo_bytes(1), "image/jpeg")},
+    )
+    assert response.status_code == 200
+    assert response.json()["back_image_url"].endswith("side=back")
+    warte_bis_gelesen(client, [card_id])
+
+    bild = client.get(f"/api/cards/{card_id}/image", params={"side": "back"})
+    assert bild.status_code == 200
+    assert bild.headers["content-type"] == "image/jpeg"
+
+
+def test_ohne_rueckseite_gibt_es_kein_rueckseitenbild(client):
+    card_id = client.post(
+        "/api/scan", files={"file": ("vorne.jpg", photo_bytes(1), "image/jpeg")}
+    ).json()["cards"][0]["id"]
+    warte_bis_gelesen(client, [card_id])
+
+    assert client.get(
+        f"/api/cards/{card_id}/image", params={"side": "back"}
+    ).status_code == 404
+
+
+def test_loeschen_entfernt_auch_die_rueckseite(client):
+    from app import config
+
+    card_id = client.post(
+        "/api/scan", files={"file": ("vorne.jpg", photo_bytes(1), "image/jpeg")}
+    ).json()["cards"][0]["id"]
+    warte_bis_gelesen(client, [card_id])
+    client.post(
+        f"/api/cards/{card_id}/back",
+        files={"file": ("hinten.jpg", photo_bytes(1), "image/jpeg")},
+    )
+    warte_bis_gelesen(client, [card_id])
+    row = db.query_one("SELECT * FROM cards WHERE id = ?", (card_id,))
+
+    client.delete(f"/api/cards/{card_id}")
+
+    assert not (config.IMAGE_DIR / row["image_file"]).exists()
+    assert not (config.IMAGE_DIR / row["back_image_file"]).exists()
diff --git a/tests/test_duplicates.py b/tests/test_duplicates.py
new file mode 100644
index 0000000..70c85b1
--- /dev/null
+++ b/tests/test_duplicates.py
@@ -0,0 +1,88 @@
+"""Dublettenerkennung. Auf Messen trifft man Leute wieder."""
+import uuid
+
+import pytest
+
+from app import db, duplicates
+
+
+def _card(**felder):
+    columns = {
+        "id": uuid.uuid4().hex,
+        "created_at": "2026-09-01T10:00:00+00:00",
+        "extract_status": "ok",
+        **felder,
+    }
+    names = ", ".join(columns)
+    db.execute(
+        f"INSERT INTO cards ({names}) VALUES ({', '.join('?' for _ in columns)})",
+        list(columns.values()),
+    )
+    return db.query_one("SELECT * FROM cards WHERE id = ?", (columns["id"],))
+
+
+@pytest.fixture(autouse=True)
+def leere_tabelle():
+    db.execute("DELETE FROM cards")
+    yield
+    db.execute("DELETE FROM cards")
+
+
+def test_gleiche_email_wird_gefunden():
+    _card(full_name="Anna Berg", email="A.Berg@Firma.de")
+    neu = _card(full_name="A. Berg", email="a.berg@firma.de")
+
+    treffer = duplicates.find(neu)
+
+    assert [t["reason"] for t in treffer] == ["gleiche E-Mail"]
+
+
+def test_telefonnummer_in_anderer_schreibweise():
+    _card(full_name="Anna Berg", phone="+49 511 1234560")
+    neu = _card(full_name="Anna B.", mobile="0511/1234560")
+
+    treffer = duplicates.find(neu)
+
+    assert [t["reason"] for t in treffer] == ["gleiche Telefonnummer"]
+
+
+def test_name_und_firma_zusammen():
+    _card(last_name="Berg", company="Berg & Partner GmbH")
+    neu = _card(last_name="berg", company="berg & partner gmbh")
+
+    assert [t["reason"] for t in duplicates.find(neu)] == ["gleicher Name und dieselbe Firma"]
+
+
+def test_gleicher_nachname_allein_reicht_nicht():
+    _card(last_name="Berg", company="Andere GmbH")
+    neu = _card(last_name="Berg", company="Berg & Partner GmbH")
+
+    assert duplicates.find(neu) == []
+
+
+def test_kurze_nummern_werden_nicht_verglichen():
+    # Eine dreistellige Durchwahl darf keine Dublette erzeugen.
+    _card(full_name="Anna Berg", phone="123")
+    neu = _card(full_name="Bea Kurz", phone="123")
+
+    assert duplicates.find(neu) == []
+
+
+def test_leere_felder_erzeugen_keine_treffer():
+    _card(full_name="Anna Berg")
+    neu = _card(full_name="Bea Kurz")
+
+    assert duplicates.find(neu) == []
+
+
+def test_die_karte_selbst_ist_keine_dublette():
+    karte = _card(full_name="Anna Berg", email="a@b.de")
+
+    assert duplicates.find(karte) == []
+
+
+def test_noch_nicht_gelesene_karten_bleiben_aussen_vor():
+    _card(full_name="Anna Berg", email="a@b.de", extract_status="offen")
+    neu = _card(full_name="Anna Berg", email="a@b.de")
+
+    assert duplicates.find(neu) == []