diff --git a/client/src/pages/BapHistory.tsx b/client/src/pages/BapHistory.tsx
index e037840..367e894 100644
--- a/client/src/pages/BapHistory.tsx
+++ b/client/src/pages/BapHistory.tsx
@@ -24,13 +24,26 @@ import {
 
 // 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';
-  // Utiliser le query param pdfPath pour passer le chemin complet au serveur
+// Nommage : AAAA-MM-JJ - Fournisseur - N°Facture.pdf
+function downloadBapPdf(
+  pdfUrl: string,
+  supplierName?: string | null,
+  invoiceNumber?: string | null,
+  validatedAt?: Date | string | null
+) {
+  const fallback = pdfUrl.split('/').pop() || 'BAP.pdf';
   const downloadUrl = `/api/download-bap?pdfPath=${encodeURIComponent(pdfUrl)}`;
+  // Construire le nom de fichier : date - fournisseur - numero.pdf
+  const datePart = validatedAt
+    ? new Date(validatedAt).toLocaleDateString('fr-CA') // format AAAA-MM-JJ
+    : '';
+  const supplierPart = (supplierName || '').replace(/[^a-zA-Z0-9à-ÿ \-]/g, '').trim();
+  const numberPart = (invoiceNumber || '').replace(/[^a-zA-Z0-9\-]/g, '').trim();
+  const parts = [datePart, supplierPart, numberPart].filter(Boolean);
+  const filename = parts.length > 0 ? `${parts.join(' - ')}.pdf` : fallback;
   const a = document.createElement('a');
   a.href = downloadUrl;
-  a.download = supplierName ? `BAP_${supplierName.replace(/[^a-zA-Z0-9]/g, '_')}.pdf` : filename;
+  a.download = filename;
   document.body.appendChild(a);
   a.click();
   document.body.removeChild(a);
@@ -266,7 +279,7 @@ export default function BapHistory() {
                                 variant="ghost"
                                 size="sm"
                                 className="h-7 px-2 text-emerald-600 hover:text-emerald-700 hover:bg-emerald-50"
-                                onClick={() => downloadBapPdf(entry.pdfUrl!, entry.supplierName)}
+                                onClick={() => downloadBapPdf(entry.pdfUrl!, entry.supplierName, entry.invoiceNumber, entry.validatedAt)}
                                 title="Télécharger le PDF annoté"
                               >
                                 <Download className="h-3.5 w-3.5" />
diff --git a/client/src/pages/InvoicesBAP.tsx b/client/src/pages/InvoicesBAP.tsx
index 9f767d7..e8fc37d 100644
--- a/client/src/pages/InvoicesBAP.tsx
+++ b/client/src/pages/InvoicesBAP.tsx
@@ -35,14 +35,25 @@ 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';
-  // Utiliser le query param pdfPath pour passer le chemin complet au serveur
+// Nommage : AAAA-MM-JJ - Fournisseur - N°Facture.pdf
+function downloadBapPdf(
+  pdfUrl: string,
+  supplierName?: string,
+  invoiceNumber?: string | null,
+  validatedAt?: Date | string | null
+) {
+  const fallback = pdfUrl.split('/').pop() || 'BAP.pdf';
   const downloadUrl = `/api/download-bap?pdfPath=${encodeURIComponent(pdfUrl)}`;
+  const datePart = validatedAt
+    ? new Date(validatedAt).toLocaleDateString('fr-CA') // AAAA-MM-JJ
+    : new Date().toLocaleDateString('fr-CA');
+  const supplierPart = (supplierName || '').replace(/[^a-zA-Z0-9à-ÿ \-]/g, '').trim();
+  const numberPart = (invoiceNumber || '').replace(/[^a-zA-Z0-9\-]/g, '').trim();
+  const parts = [datePart, supplierPart, numberPart].filter(Boolean);
+  const filename = parts.length > 0 ? `${parts.join(' - ')}.pdf` : fallback;
   const a = document.createElement('a');
   a.href = downloadUrl;
-  a.download = supplierName ? `BAP_${supplierName.replace(/[^a-zA-Z0-9]/g, '_')}.pdf` : filename;
+  a.download = filename;
   document.body.appendChild(a);
   a.click();
   document.body.removeChild(a);
@@ -713,7 +724,7 @@ export default function InvoicesBAP() {
                                       variant="outline"
                                       className="h-8 px-2 text-blue-600 border-blue-300 hover:bg-blue-50"
                                       title="Télécharger le PDF annoté BAP"
-                                      onClick={() => downloadBapPdf(bapPdfUrls[invoice.id], invoice.supplierName || undefined)}
+                                      onClick={() => downloadBapPdf(bapPdfUrls[invoice.id], invoice.supplierName || undefined, invoice.invoiceNumber, invoice.bapValidatedAt)}
                                     >
                                       <Download className="h-4 w-4" />
                                     </Button>