diff --git a/client/src/pages/BapHistory.tsx b/client/src/pages/BapHistory.tsx
index 28d663d..e037840 100644
--- a/client/src/pages/BapHistory.tsx
+++ b/client/src/pages/BapHistory.tsx
@@ -23,9 +23,11 @@ import {
 } from "lucide-react";
 
 // Helper : télécharge un PDF annoté BAP depuis son URL de stockage
+// pdfUrl peut être : '/storage/2026-04/BAP_xxx.pdf' ou '/storage/BAP_xxx.pdf'
 function downloadBapPdf(pdfUrl: string, supplierName?: string | null) {
   const filename = pdfUrl.split('/').pop() || 'BAP.pdf';
-  const downloadUrl = `/api/download-bap/${filename}`;
+  // Utiliser le query param pdfPath pour passer le chemin complet au serveur
+  const downloadUrl = `/api/download-bap?pdfPath=${encodeURIComponent(pdfUrl)}`;
   const a = document.createElement('a');
   a.href = downloadUrl;
   a.download = supplierName ? `BAP_${supplierName.replace(/[^a-zA-Z0-9]/g, '_')}.pdf` : filename;
diff --git a/client/src/pages/InvoicesBAP.tsx b/client/src/pages/InvoicesBAP.tsx
index 8038ade..9f767d7 100644
--- a/client/src/pages/InvoicesBAP.tsx
+++ b/client/src/pages/InvoicesBAP.tsx
@@ -35,9 +35,11 @@ import { trpc } from "@/lib/trpc";
 import { Search, FileText, Download, FileSpreadsheet, Trash2, Edit, Trash, CheckCircle, CheckCircle2, ShieldCheck } from "lucide-react";
 
 // Helper : télécharge un PDF annoté BAP depuis son URL de stockage
+// pdfUrl peut être : '/storage/2026-04/BAP_xxx.pdf' ou '/storage/BAP_xxx.pdf'
 function downloadBapPdf(pdfUrl: string, supplierName?: string) {
   const filename = pdfUrl.split('/').pop() || 'BAP.pdf';
-  const downloadUrl = `/api/download-bap/${filename}`;
+  // Utiliser le query param pdfPath pour passer le chemin complet au serveur
+  const downloadUrl = `/api/download-bap?pdfPath=${encodeURIComponent(pdfUrl)}`;
   const a = document.createElement('a');
   a.href = downloadUrl;
   a.download = supplierName ? `BAP_${supplierName.replace(/[^a-zA-Z0-9]/g, '_')}.pdf` : filename;
diff --git a/server/_core/index.ts b/server/_core/index.ts
index e1c12a4..45b6ed9 100644
--- a/server/_core/index.ts
+++ b/server/_core/index.ts
@@ -41,18 +41,57 @@ async function startServer() {
   app.use("/storage", express.static("storage"));
 
   // Route de téléchargement forcé du PDF annoté BAP
-  app.get("/api/download-bap/:filename", (req, res) => {
-    const filename = path.basename(req.params.filename); // sécurité : pas de path traversal
-    const storagePath = path.resolve("storage", filename);
+  // Accepte les chemins avec sous-dossiers : /api/download-bap/2026-04/filename.pdf
+  // ou via query param pdfPath : /api/download-bap/file.pdf?pdfPath=/storage/2026-04/file.pdf
+  app.get("/api/download-bap", (req, res) => {
+    // Mode 1 : query param pdfPath (chemin complet depuis /storage/...)
+    const pdfPath = req.query.pdfPath as string | undefined;
+    if (!pdfPath) {
+      res.status(400).json({ error: "Paramètre pdfPath manquant" });
+      return;
+    }
+    // Sécurité : s'assurer que le chemin est bien dans le dossier storage
+    const normalized = path.normalize(pdfPath).replace(/^\/+/, '');
+    if (normalized.startsWith('..') || !normalized.startsWith('storage')) {
+      res.status(403).json({ error: "Accès refusé" });
+      return;
+    }
+    const storagePath = path.resolve(normalized);
     if (!fs.existsSync(storagePath)) {
       res.status(404).json({ error: "Fichier introuvable" });
       return;
     }
-    res.setHeader("Content-Disposition", `attachment; filename="${filename}"`);
+    const filename = path.basename(storagePath);
+    res.setHeader("Content-Disposition", `attachment; filename="${encodeURIComponent(filename)}"`);
     res.setHeader("Content-Type", "application/pdf");
     res.sendFile(storagePath);
   });
 
+  // Compat. ancienne route avec :filename (sans sous-dossier)
+  app.get("/api/download-bap/:filename", (req, res) => {
+    const filename = path.basename(req.params.filename);
+    // Chercher dans tous les sous-dossiers de storage
+    const storageRoot = path.resolve("storage");
+    let found: string | null = null;
+    try {
+      const subdirs = fs.readdirSync(storageRoot);
+      for (const sub of subdirs) {
+        const candidate = path.join(storageRoot, sub, filename);
+        if (fs.existsSync(candidate)) { found = candidate; break; }
+      }
+      // Aussi essayer directement dans storage/
+      const direct = path.join(storageRoot, filename);
+      if (!found && fs.existsSync(direct)) found = direct;
+    } catch { /* ignore */ }
+    if (!found) {
+      res.status(404).json({ error: "Fichier introuvable" });
+      return;
+    }
+    res.setHeader("Content-Disposition", `attachment; filename="${encodeURIComponent(filename)}"`);
+    res.setHeader("Content-Type", "application/pdf");
+    res.sendFile(found);
+  });
+
   // tRPC API
   app.use(
     "/api/trpc",