diff --git a/backend/src/db/index.js b/backend/src/db/index.js
index e77d582..e0c873b 100644
--- a/backend/src/db/index.js
+++ b/backend/src/db/index.js
@@ -2075,4 +2075,15 @@ console.log('[DB] Migrations 2FA OK');
   }
 }
 
+// ── Migration : compteur de doublons ignorés sur imports ──────────────────
+// Distingue les lignes ignorées car identiques à une ligne déjà en base
+// (rows_duplicates) des lignes ignorées pour une autre raison (rows_skipped
+// reste le total ; rows_duplicates est un sous-ensemble informatif).
+{
+  const importsCols = db.prepare('PRAGMA table_info(imports)').all().map(c => c.name);
+  if (!importsCols.includes('rows_duplicates')) {
+    db.exec('ALTER TABLE imports ADD COLUMN rows_duplicates INTEGER NOT NULL DEFAULT 0');
+  }
+}
+
 export default db;
diff --git a/backend/src/routes/imports.js b/backend/src/routes/imports.js
index 37f145b..0a5c6fc 100644
--- a/backend/src/routes/imports.js
+++ b/backend/src/routes/imports.js
@@ -137,7 +137,7 @@ router.post('/apply', (req, res, next) => {
       invNameMap = new Map(invRows.map(i => [normalizeName(i.nom_projet), i.id]));
     }
 
-    let inserted = 0, skipped = 0;
+    let inserted = 0, skipped = 0, duplicates = 0;
     const errors = [];
 
     const tx = db.transaction(() => {
@@ -153,22 +153,48 @@ router.post('/apply', (req, res, next) => {
           };
 
           if (module === 'depots_retraits') {
+            const plateformeId = resolveRefId(v('plateforme_id'), platIdSet, platNameMap, 'Plateforme');
+            const dateOperation = normaliseDate(v('date_operation'));
+            const type          = normaliseType(v('type'));
+            const montant       = num(v('montant'));
+
+            // Anti-doublon : même investisseur + plateforme + date + type + montant
+            const dup = db.prepare(`
+              SELECT id FROM depots_retraits
+              WHERE investisseur_id = ? AND plateforme_id = ? AND date_operation = ?
+                AND type = ? AND ABS(montant - ?) < 0.005
+              LIMIT 1
+            `).get(req.investisseur.id, plateformeId, dateOperation, type, montant);
+            if (dup) { duplicates++; continue; }
+
             db.prepare(`
               INSERT INTO depots_retraits
                 (investisseur_id, plateforme_id, date_operation, type, montant, libelle, reference, source)
               VALUES (?,?,?,?,?,?,?,?)
             `).run(
               req.investisseur.id,
-              resolveRefId(v('plateforme_id'), platIdSet, platNameMap, 'Plateforme'),
-              normaliseDate(v('date_operation')),
-              normaliseType(v('type')),
-              num(v('montant')),
+              plateformeId,
+              dateOperation,
+              type,
+              montant,
               v('libelle') || null,
               v('reference') || null,
               srcLabel,
             );
 
           } else if (module === 'investissements') {
+            const plateformeId    = resolveRefId(v('plateforme_id'), platIdSet, platNameMap, 'Plateforme');
+            const nomProjet       = String(v('nom_projet'));
+            const dateSouscription = normaliseDate(v('date_souscription'));
+
+            // Anti-doublon : même investisseur + plateforme + nom du projet + date de souscription
+            const dup = db.prepare(`
+              SELECT id FROM investissements
+              WHERE investisseur_id = ? AND plateforme_id = ? AND nom_projet = ? AND date_souscription = ?
+              LIMIT 1
+            `).get(req.investisseur.id, plateformeId, nomProjet, dateSouscription);
+            if (dup) { duplicates++; continue; }
+
             db.prepare(`
               INSERT INTO investissements
                 (investisseur_id, plateforme_id, nom_projet, emetteur, date_souscription,
@@ -177,10 +203,10 @@ router.post('/apply', (req, res, next) => {
               VALUES (?,?,?,?,?,?,?,?,?,?,?,?,?,?,?)
             `).run(
               req.investisseur.id,
-              resolveRefId(v('plateforme_id'), platIdSet, platNameMap, 'Plateforme'),
-              String(v('nom_projet')),
+              plateformeId,
+              nomProjet,
               v('emetteur') || null,
-              normaliseDate(v('date_souscription')),
+              dateSouscription,
               v('date_premiere_echeance') ? normaliseDate(v('date_premiere_echeance')) : null,
               v('date_cible') ? normaliseDate(v('date_cible')) : null,
               num(v('montant_investi')),
@@ -194,6 +220,8 @@ router.post('/apply', (req, res, next) => {
             );
 
           } else if (module === 'remboursements') {
+            const investissementId = resolveRefId(v('investissement_id'), invIdSet, invNameMap, 'Investissement');
+            const dateRemb    = normaliseDate(v('date_remb'));
             const capital     = num(v('capital'));
             const cashback    = num(v('cashback'));
             const bruts       = num(v('interets_bruts'));
@@ -201,14 +229,24 @@ router.post('/apply', (req, res, next) => {
             const pf          = num(v('prelev_forfaitaire'));
             const interets_nets = Math.round((bruts - ps - pf) * 100) / 100;
             const net_recu      = Math.round((capital + cashback + interets_nets) * 100) / 100;
+
+            // Anti-doublon : même investissement + date + capital + intérêts bruts
+            const dup = db.prepare(`
+              SELECT id FROM remboursements
+              WHERE investissement_id = ? AND date_remb = ?
+                AND ABS(capital - ?) < 0.005 AND ABS(interets_bruts - ?) < 0.005
+              LIMIT 1
+            `).get(investissementId, dateRemb, capital, bruts);
+            if (dup) { duplicates++; continue; }
+
             db.prepare(`
               INSERT INTO remboursements
                 (investissement_id, date_remb, capital, cashback, interets_bruts, prelev_sociaux,
                  prelev_forfaitaire, interets_nets, net_recu, statut, source)
               VALUES (?,?,?,?,?,?,?,?,?,?,?)
             `).run(
-              resolveRefId(v('investissement_id'), invIdSet, invNameMap, 'Investissement'),
-              normaliseDate(v('date_remb')),
+              investissementId,
+              dateRemb,
               capital, cashback, bruts, ps, pf, interets_nets, net_recu,
               v('statut') || 'paye',
               srcLabel,
@@ -226,8 +264,8 @@ router.post('/apply', (req, res, next) => {
               v('url') || null,
               v('notes') || null,
             );
-            // changes = 0 means the row was ignored (nom already exists)
-            if (r.changes === 0) throw new Error(`Plateforme "${nom}" existe déjà — ignorée`);
+            // changes = 0 means the row was ignored (nom already exists) — doublon, pas une erreur
+            if (r.changes === 0) { duplicates++; continue; }
 
           } else if (module === 'taux_pfu') {
             const annee = parseInt(v('annee'), 10);
@@ -258,8 +296,8 @@ router.post('/apply', (req, res, next) => {
     tx();
 
     db.prepare(`
-      INSERT INTO imports (user_id, investisseur_id, module, filename, rows_total, rows_inserted, rows_skipped, mapping_json)
-      VALUES (?,?,?,?,?,?,?,?)
+      INSERT INTO imports (user_id, investisseur_id, module, filename, rows_total, rows_inserted, rows_skipped, rows_duplicates, mapping_json)
+      VALUES (?,?,?,?,?,?,?,?,?)
     `).run(
       req.user.id,
       req.investisseur?.id ?? null,
@@ -268,13 +306,14 @@ router.post('/apply', (req, res, next) => {
       rows.length,
       inserted,
       skipped,
+      duplicates,
       JSON.stringify(mapping),
     );
 
     // Clean up temp file
     try { fs.unlinkSync(tempPath); } catch { /* */ }
 
-    res.json({ inserted, skipped, total: rows.length, errors: errors.slice(0, 50) });
+    res.json({ inserted, skipped, duplicates, total: rows.length, errors: errors.slice(0, 50) });
   } catch (e) { next(e); }
 });
 
diff --git a/frontend/src/pages/settings/ImportsSection.jsx b/frontend/src/pages/settings/ImportsSection.jsx
index aa95bc9..c2db01d 100644
--- a/frontend/src/pages/settings/ImportsSection.jsx
+++ b/frontend/src/pages/settings/ImportsSection.jsx
@@ -406,7 +406,11 @@ export default function ImportsSection() {
       });
       setResult({
         ok: true,
-        msg: `✔ Import terminé : ${r.inserted} / ${r.total} lignes insérées${r.skipped > 0 ? `, ${r.skipped} ignorées` : ''}.${r.errors?.length > 0 ? ` (${r.errors.length} avertissement(s))` : ''}`,
+        msg: `✔ Import terminé : ${r.inserted} / ${r.total} lignes insérées`
+          + (r.duplicates > 0 ? `, ${r.duplicates} doublon(s) ignoré(s)` : '')
+          + (r.skipped > 0 ? `, ${r.skipped} ignorée(s)` : '')
+          + '.'
+          + (r.errors?.length > 0 ? ` (${r.errors.length} avertissement(s))` : ''),
       });
       setPreview(null); setFile(null); setMapping({}); setDefaults({});
       api.get('/imports/history').then(setHistory).catch(() => {});
@@ -602,12 +606,12 @@ export default function ImportsSection() {
           <thead>
             <tr>
               <th>Date</th><th>Module</th><th>Fichier</th>
-              <th className="num">Total</th><th className="num">OK</th><th className="num">KO</th>
+              <th className="num">Total</th><th className="num">OK</th><th className="num">Doublons</th><th className="num">KO</th>
             </tr>
           </thead>
           <tbody>
             {history.length === 0 && (
-              <tr><td colSpan={6} className="text-muted" style={{ textAlign: 'center' }}>Aucun import</td></tr>
+              <tr><td colSpan={7} className="text-muted" style={{ textAlign: 'center' }}>Aucun import</td></tr>
             )}
             {history.map(h => (
               <tr key={h.id}>
@@ -616,6 +620,7 @@ export default function ImportsSection() {
                 <td className="text-muted" style={{ fontSize: 11 }}>{h.filename}</td>
                 <td className="num">{h.rows_total}</td>
                 <td className="num" style={{ color: 'var(--success)' }}>{h.rows_inserted}</td>
+                <td className="num" style={{ color: h.rows_duplicates > 0 ? 'var(--text-muted)' : undefined }}>{h.rows_duplicates ?? 0}</td>
                 <td className="num" style={{ color: h.rows_skipped > 0 ? 'var(--warning)' : undefined }}>{h.rows_skipped}</td>
               </tr>
             ))}