diff --git a/src/components/shared/CategoryCombobox.tsx b/src/components/shared/CategoryCombobox.tsx
new file mode 100644
index 0000000..e982363
--- /dev/null
+++ b/src/components/shared/CategoryCombobox.tsx
@@ -0,0 +1,189 @@
+import { useState, useRef, useEffect, useCallback } from "react";
+import type { Category } from "../../shared/types";
+
+interface CategoryComboboxProps {
+  categories: Category[];
+  value: number | null;
+  onChange: (id: number | null) => void;
+  placeholder?: string;
+  compact?: boolean;
+  /** Extra options shown before the category list (e.g. "All categories", "Uncategorized") */
+  extraOptions?: Array<{ value: string; label: string }>;
+  /** Called when an extra option is selected */
+  onExtraSelect?: (value: string) => void;
+  /** Currently active extra option value (for display) */
+  activeExtra?: string | null;
+}
+
+export default function CategoryCombobox({
+  categories,
+  value,
+  onChange,
+  placeholder = "",
+  compact = false,
+  extraOptions,
+  onExtraSelect,
+  activeExtra,
+}: CategoryComboboxProps) {
+  const [open, setOpen] = useState(false);
+  const [query, setQuery] = useState("");
+  const [highlightIndex, setHighlightIndex] = useState(0);
+  const inputRef = useRef<HTMLInputElement>(null);
+  const listRef = useRef<HTMLUListElement>(null);
+  const containerRef = useRef<HTMLDivElement>(null);
+
+  // Build display label
+  const selectedCategory = categories.find((c) => c.id === value);
+  const displayLabel =
+    activeExtra != null
+      ? extraOptions?.find((o) => o.value === activeExtra)?.label ?? ""
+      : selectedCategory?.name ?? "";
+
+  // Filter categories
+  const lowerQuery = query.toLowerCase();
+  const filtered = query
+    ? categories.filter((c) => c.name.toLowerCase().includes(lowerQuery))
+    : categories;
+
+  const filteredExtras = extraOptions
+    ? query
+      ? extraOptions.filter((o) => o.label.toLowerCase().includes(lowerQuery))
+      : extraOptions
+    : [];
+
+  const totalItems = filteredExtras.length + filtered.length;
+
+  // Scroll highlighted item into view
+  useEffect(() => {
+    if (open && listRef.current) {
+      const el = listRef.current.children[highlightIndex] as HTMLElement | undefined;
+      el?.scrollIntoView({ block: "nearest" });
+    }
+  }, [highlightIndex, open]);
+
+  // Close on outside click
+  useEffect(() => {
+    if (!open) return;
+    const handler = (e: MouseEvent) => {
+      if (containerRef.current && !containerRef.current.contains(e.target as Node)) {
+        setOpen(false);
+        setQuery("");
+      }
+    };
+    document.addEventListener("mousedown", handler);
+    return () => document.removeEventListener("mousedown", handler);
+  }, [open]);
+
+  const selectItem = useCallback(
+    (index: number) => {
+      if (index < filteredExtras.length) {
+        onExtraSelect?.(filteredExtras[index].value);
+      } else {
+        const cat = filtered[index - filteredExtras.length];
+        if (cat) onChange(cat.id);
+      }
+      setOpen(false);
+      setQuery("");
+      inputRef.current?.blur();
+    },
+    [filteredExtras, filtered, onChange, onExtraSelect]
+  );
+
+  const handleKeyDown = (e: React.KeyboardEvent) => {
+    if (!open) {
+      if (e.key === "ArrowDown" || e.key === "Enter") {
+        e.preventDefault();
+        setOpen(true);
+        setHighlightIndex(0);
+      }
+      return;
+    }
+
+    switch (e.key) {
+      case "ArrowDown":
+        e.preventDefault();
+        setHighlightIndex((i) => (i + 1) % totalItems);
+        break;
+      case "ArrowUp":
+        e.preventDefault();
+        setHighlightIndex((i) => (i - 1 + totalItems) % totalItems);
+        break;
+      case "Enter":
+        e.preventDefault();
+        if (totalItems > 0) selectItem(highlightIndex);
+        break;
+      case "Escape":
+        e.preventDefault();
+        setOpen(false);
+        setQuery("");
+        inputRef.current?.blur();
+        break;
+    }
+  };
+
+  const py = compact ? "py-1" : "py-2";
+  const px = compact ? "px-2" : "px-3";
+
+  return (
+    <div ref={containerRef} className="relative">
+      <input
+        ref={inputRef}
+        type="text"
+        value={open ? query : displayLabel}
+        placeholder={placeholder || displayLabel}
+        onChange={(e) => {
+          setQuery(e.target.value);
+          setHighlightIndex(0);
+          if (!open) setOpen(true);
+        }}
+        onFocus={() => {
+          setOpen(true);
+          setQuery("");
+          setHighlightIndex(0);
+        }}
+        onKeyDown={handleKeyDown}
+        className={`w-full ${px} ${py} text-sm rounded-lg border border-[var(--border)] bg-[var(--background)] text-[var(--foreground)] placeholder:text-[var(--muted-foreground)] focus:outline-none focus:ring-1 focus:ring-[var(--primary)]`}
+      />
+      {open && totalItems > 0 && (
+        <ul
+          ref={listRef}
+          className="absolute z-50 mt-1 max-h-60 w-full overflow-auto rounded-lg border border-[var(--border)] bg-[var(--card)] shadow-lg"
+        >
+          {filteredExtras.map((opt, i) => (
+            <li
+              key={`extra-${opt.value}`}
+              onMouseDown={(e) => e.preventDefault()}
+              onClick={() => selectItem(i)}
+              onMouseEnter={() => setHighlightIndex(i)}
+              className={`${px} ${py} text-sm cursor-pointer ${
+                i === highlightIndex
+                  ? "bg-[var(--primary)] text-white"
+                  : "text-[var(--foreground)] hover:bg-[var(--muted)]"
+              }`}
+            >
+              {opt.label}
+            </li>
+          ))}
+          {filtered.map((cat, i) => {
+            const idx = filteredExtras.length + i;
+            return (
+              <li
+                key={cat.id}
+                onMouseDown={(e) => e.preventDefault()}
+                onClick={() => selectItem(idx)}
+                onMouseEnter={() => setHighlightIndex(idx)}
+                className={`${px} ${py} text-sm cursor-pointer ${
+                  idx === highlightIndex
+                    ? "bg-[var(--primary)] text-white"
+                    : "text-[var(--foreground)] hover:bg-[var(--muted)]"
+                }`}
+              >
+                {cat.name}
+              </li>
+            );
+          })}
+        </ul>
+      )}
+    </div>
+  );
+}
diff --git a/src/components/transactions/TransactionFilterBar.tsx b/src/components/transactions/TransactionFilterBar.tsx
index 817346c..1fcad90 100644
--- a/src/components/transactions/TransactionFilterBar.tsx
+++ b/src/components/transactions/TransactionFilterBar.tsx
@@ -1,6 +1,8 @@
+import { useMemo } from "react";
 import { useTranslation } from "react-i18next";
 import { Search } from "lucide-react";
 import type { TransactionFilters, Category, ImportSource } from "../../shared/types";
+import CategoryCombobox from "../shared/CategoryCombobox";
 
 interface TransactionFilterBarProps {
   filters: TransactionFilters;
@@ -17,6 +19,14 @@ export default function TransactionFilterBar({
 }: TransactionFilterBarProps) {
   const { t } = useTranslation();
 
+  const categoryExtras = useMemo(
+    () => [
+      { value: "", label: t("transactions.filters.allCategories") },
+      { value: "uncategorized", label: t("transactions.filters.uncategorized") },
+    ],
+    [t]
+  );
+
   const activeCount = [
     filters.search,
     filters.categoryId !== null || filters.uncategorizedOnly,
@@ -44,34 +54,34 @@ export default function TransactionFilterBar({
         </div>
 
         {/* Category */}
-        <select
-          value={
-            filters.uncategorizedOnly
-              ? "uncategorized"
-              : filters.categoryId?.toString() ?? ""
-          }
-          onChange={(e) => {
-            const val = e.target.value;
-            if (val === "uncategorized") {
-              onFilterChange("uncategorizedOnly", true);
-              onFilterChange("categoryId", null);
-            } else {
+        <div className="min-w-[180px]">
+          <CategoryCombobox
+            categories={categories}
+            value={filters.categoryId}
+            onChange={(id) => {
               onFilterChange("uncategorizedOnly", false);
-              onFilterChange("categoryId", val ? Number(val) : null);
+              onFilterChange("categoryId", id);
+            }}
+            placeholder={t("transactions.filters.allCategories")}
+            extraOptions={categoryExtras}
+            activeExtra={
+              filters.uncategorizedOnly
+                ? "uncategorized"
+                : filters.categoryId === null
+                  ? ""
+                  : null
             }
-          }}
-          className="px-3 py-2 text-sm rounded-lg border border-[var(--border)] bg-[var(--background)] text-[var(--foreground)] focus:outline-none focus:ring-1 focus:ring-[var(--primary)]"
-        >
-          <option value="">{t("transactions.filters.allCategories")}</option>
-          <option value="uncategorized">
-            {t("transactions.filters.uncategorized")}
-          </option>
-          {categories.map((c) => (
-            <option key={c.id} value={c.id}>
-              {c.name}
-            </option>
-          ))}
-        </select>
+            onExtraSelect={(val) => {
+              if (val === "uncategorized") {
+                onFilterChange("uncategorizedOnly", true);
+                onFilterChange("categoryId", null);
+              } else {
+                onFilterChange("uncategorizedOnly", false);
+                onFilterChange("categoryId", null);
+              }
+            }}
+          />
+        </div>
 
         {/* Source */}
         <select
diff --git a/src/components/transactions/TransactionTable.tsx b/src/components/transactions/TransactionTable.tsx
index 080e963..bf2da1c 100644
--- a/src/components/transactions/TransactionTable.tsx
+++ b/src/components/transactions/TransactionTable.tsx
@@ -1,4 +1,4 @@
-import { Fragment, useState } from "react";
+import { Fragment, useState, useMemo } from "react";
 import { useTranslation } from "react-i18next";
 import { ChevronUp, ChevronDown, MessageSquare } from "lucide-react";
 import type {
@@ -6,6 +6,7 @@ import type {
   TransactionSort,
   Category,
 } from "../../shared/types";
+import CategoryCombobox from "../shared/CategoryCombobox";
 
 interface TransactionTableProps {
   rows: TransactionRow[];
@@ -43,6 +44,10 @@ export default function TransactionTable({
   const { t } = useTranslation();
   const [expandedId, setExpandedId] = useState<number | null>(null);
   const [editingNotes, setEditingNotes] = useState("");
+  const noCategoryExtra = useMemo(
+    () => [{ value: "", label: t("transactions.table.noCategory") }],
+    [t]
+  );
 
   if (rows.length === 0) {
     return (
@@ -116,25 +121,16 @@ export default function TransactionTable({
                   })}
                 </td>
                 <td className="px-3 py-2">
-                  <select
-                    value={row.category_id?.toString() ?? ""}
-                    onChange={(e) =>
-                      onCategoryChange(
-                        row.id,
-                        e.target.value ? Number(e.target.value) : null
-                      )
-                    }
-                    className="w-full px-2 py-1 text-sm rounded border border-[var(--border)] bg-[var(--background)] text-[var(--foreground)] focus:outline-none focus:ring-1 focus:ring-[var(--primary)]"
-                  >
-                    <option value="">
-                      {t("transactions.table.noCategory")}
-                    </option>
-                    {categories.map((c) => (
-                      <option key={c.id} value={c.id}>
-                        {c.name}
-                      </option>
-                    ))}
-                  </select>
+                  <CategoryCombobox
+                    categories={categories}
+                    value={row.category_id}
+                    onChange={(id) => onCategoryChange(row.id, id)}
+                    placeholder={t("transactions.table.noCategory")}
+                    compact
+                    extraOptions={noCategoryExtra}
+                    activeExtra={row.category_id === null ? "" : null}
+                    onExtraSelect={() => onCategoryChange(row.id, null)}
+                  />
                 </td>
                 <td className="px-3 py-2 text-center">
                   <button
diff --git a/src/hooks/useImportWizard.ts b/src/hooks/useImportWizard.ts
index a4d5ffd..abb841e 100644
--- a/src/hooks/useImportWizard.ts
+++ b/src/hooks/useImportWizard.ts
@@ -552,17 +552,42 @@ export function useImportWizard() {
         }))
       );
 
-      const duplicateIndices = new Set(duplicateMatches.map((d) => d.rowIndex));
+      // Detect intra-batch duplicates (rows that appear more than once within the import)
+      const dbDuplicateIndices = new Set(duplicateMatches.map((d) => d.rowIndex));
+      const seenKeys = new Set<string>();
+      const batchDuplicateIndices = new Set<number>();
+
+      for (let i = 0; i < validRows.length; i++) {
+        if (dbDuplicateIndices.has(i)) continue; // already flagged as DB duplicate
+        const r = validRows[i].parsed!;
+        const key = `${r.date}|${r.description}|${r.amount}`;
+        if (seenKeys.has(key)) {
+          batchDuplicateIndices.add(i);
+        } else {
+          seenKeys.add(key);
+        }
+      }
+
+      const duplicateIndices = new Set([...dbDuplicateIndices, ...batchDuplicateIndices]);
       const newRows = validRows.filter(
         (_, i) => !duplicateIndices.has(i)
       );
-      const duplicateRows = duplicateMatches.map((d) => ({
-        rowIndex: d.rowIndex,
-        date: d.date,
-        description: d.description,
-        amount: d.amount,
-        existingTransactionId: d.existingTransactionId,
-      }));
+      const duplicateRows = [
+        ...duplicateMatches.map((d) => ({
+          rowIndex: d.rowIndex,
+          date: d.date,
+          description: d.description,
+          amount: d.amount,
+          existingTransactionId: d.existingTransactionId,
+        })),
+        ...[...batchDuplicateIndices].map((i) => ({
+          rowIndex: i,
+          date: validRows[i].parsed!.date,
+          description: validRows[i].parsed!.description,
+          amount: validRows[i].parsed!.amount,
+          existingTransactionId: -1,
+        })),
+      ];
 
       dispatch({
         type: "SET_DUPLICATE_RESULT",
diff --git a/src/i18n/locales/en.json b/src/i18n/locales/en.json
index af78788..2fec211 100644
--- a/src/i18n/locales/en.json
+++ b/src/i18n/locales/en.json
@@ -94,7 +94,8 @@
       "noneFound": "No duplicates found",
       "skip": "Skip duplicates",
       "includeAll": "Import all",
-      "summary": "Total: {{total}} rows — {{new}} new — {{duplicates}} duplicate(s)"
+      "summary": "Total: {{total}} rows — {{new}} new — {{duplicates}} duplicate(s)",
+      "withinBatch": "Duplicate within imported files"
     },
     "confirm": {
       "title": "Import Confirmation",
diff --git a/src/i18n/locales/fr.json b/src/i18n/locales/fr.json
index 94de41d..457ee09 100644
--- a/src/i18n/locales/fr.json
+++ b/src/i18n/locales/fr.json
@@ -94,7 +94,8 @@
       "noneFound": "Aucun doublon détecté",
       "skip": "Ignorer les doublons",
       "includeAll": "Tout importer",
-      "summary": "Total : {{total}} lignes — {{new}} nouvelles — {{duplicates}} doublon(s)"
+      "summary": "Total : {{total}} lignes — {{new}} nouvelles — {{duplicates}} doublon(s)",
+      "withinBatch": "Doublon entre fichiers importés"
     },
     "confirm": {
       "title": "Confirmation de l'import",
diff --git a/src/services/importSourceService.ts b/src/services/importSourceService.ts
index 9f68460..dc47278 100644
--- a/src/services/importSourceService.ts
+++ b/src/services/importSourceService.ts
@@ -34,7 +34,15 @@ export async function createSource(
   const db = await getDb();
   const result = await db.execute(
     `INSERT INTO import_sources (name, description, date_format, delimiter, encoding, column_mapping, skip_lines)
-     VALUES ($1, $2, $3, $4, $5, $6, $7)`,
+     VALUES ($1, $2, $3, $4, $5, $6, $7)
+     ON CONFLICT(name) DO UPDATE SET
+       description = excluded.description,
+       date_format = excluded.date_format,
+       delimiter = excluded.delimiter,
+       encoding = excluded.encoding,
+       column_mapping = excluded.column_mapping,
+       skip_lines = excluded.skip_lines,
+       updated_at = CURRENT_TIMESTAMP`,
     [
       source.name,
       source.description || null,
@@ -45,7 +53,10 @@ export async function createSource(
       source.skip_lines,
     ]
   );
-  return result.lastInsertId as number;
+  // On conflict, lastInsertId may be 0 — look up the existing row
+  if (result.lastInsertId) return result.lastInsertId as number;
+  const existing = await getSourceByName(source.name);
+  return existing!.id;
 }
 
 export async function updateSource(