diff --git a/client/src/pages/InvoicesBAP.tsx b/client/src/pages/InvoicesBAP.tsx
index a8f1abd..d80c0af 100644
--- a/client/src/pages/InvoicesBAP.tsx
+++ b/client/src/pages/InvoicesBAP.tsx
@@ -32,6 +32,7 @@ import {
   TableRow,
 } from "@/components/ui/table";
 import { trpc } from "@/lib/trpc";
+import { BAP_MIN_QUALITY_SCORE, meetsBapQualityThreshold } from "@shared/bapEligibility";
 import { Search, FileText, Download, FileSpreadsheet, Trash2, Edit, Trash, CheckCircle, CheckCircle2, ShieldCheck, RefreshCw, FolderDown, ChevronDown, ChevronRight, ChevronsUpDown, CalendarDays, ArrowUpDown, ArrowUp, ArrowDown } from "lucide-react";
 import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from "@/components/ui/select";
 
@@ -394,7 +395,7 @@ export default function InvoicesBAP() {
   // Déclarée ici (avant filteredInvoices et statusCounts) pour éviter le hoisting error
   const isEligibleForBAPValidation = (invoice: any) => {
     return (
-      (invoice.qualityScore || 0) === 100 &&
+      meetsBapQualityThreshold(invoice.qualityScore) &&
       invoice.exportStatus !== "exported" &&
       invoice.isSubscription === 0 &&
       invoice.serviceConcerne &&
@@ -526,19 +527,19 @@ export default function InvoicesBAP() {
 
   const getQualityBadge = (score: number | null) => {
     if (score === null) return <Badge variant="outline">-</Badge>;
-    if (score === 100) return <Badge className="bg-green-100 text-green-800 hover:bg-green-100">{score}%</Badge>;
+    if (meetsBapQualityThreshold(score)) return <Badge className="bg-green-100 text-green-800 hover:bg-green-100">{score}%</Badge>;
     if (score >= 80) return <Badge className="bg-yellow-100 text-yellow-800 hover:bg-yellow-100">{score}%</Badge>;
     return <Badge className="bg-red-100 text-red-800 hover:bg-red-100">{score}%</Badge>;
   };
 
   const isEligibleForExport = (invoice: any) => {
     // Une facture BAP est exportable si :
-    // 1. Score = 100%
+    // 1. Score >= 90 % (seuil BAP)
     // 2. Type d'achat rempli
     // 3. Service concerné rempli
     // 4. Ventilation comptable remplie
     return (
-      (invoice.qualityScore || 0) === 100 &&
+      meetsBapQualityThreshold(invoice.qualityScore) &&
       invoice.typeAchat &&
       invoice.serviceConcerne &&
       invoice.ventilationComptable
@@ -549,7 +550,7 @@ export default function InvoicesBAP() {
 
   const getBAPValidationTooltip = (invoice: any): string => {
     const reasons: string[] = [];
-    if ((invoice.qualityScore || 0) < 100) reasons.push("Score < 100%");
+    if (!meetsBapQualityThreshold(invoice.qualityScore)) reasons.push(`Score < ${BAP_MIN_QUALITY_SCORE}%`);
     if (invoice.exportStatus === "exported") reasons.push("Déjà exportée");
     if (invoice.isSubscription !== 0) reasons.push("Marquée comme abonnement");
     if (!invoice.serviceConcerne) reasons.push("Service manquant");
@@ -655,7 +656,7 @@ export default function InvoicesBAP() {
             </Button>
             <Button
               onClick={() => {
-                if (confirm("Valider en BAP toutes les factures éligibles (score 100%, champs remplis, non abonnement) ? Les PDFs annotés seront générés automatiquement.")) {
+                if (confirm(`Valider en BAP toutes les factures éligibles (score ≥ ${BAP_MIN_QUALITY_SCORE}%, champs remplis, non abonnement) ? Les PDFs annotés seront générés automatiquement.`)) {
                   validateBAPBulkMutation.mutate();
                 }
               }}
diff --git a/server/bapEligibility.test.ts b/server/bapEligibility.test.ts
new file mode 100644
index 0000000..827a66e
--- /dev/null
+++ b/server/bapEligibility.test.ts
@@ -0,0 +1,16 @@
+import { describe, expect, it } from "vitest";
+import { BAP_MIN_QUALITY_SCORE, meetsBapQualityThreshold } from "@shared/bapEligibility";
+
+describe("meetsBapQualityThreshold", () => {
+  it("autorise exactement le seuil de 90 %", () => {
+    expect(BAP_MIN_QUALITY_SCORE).toBe(90);
+    expect(meetsBapQualityThreshold(90)).toBe(true);
+    expect(meetsBapQualityThreshold(100)).toBe(true);
+  });
+
+  it("refuse les scores inférieurs ou absents", () => {
+    expect(meetsBapQualityThreshold(89)).toBe(false);
+    expect(meetsBapQualityThreshold(null)).toBe(false);
+    expect(meetsBapQualityThreshold(undefined)).toBe(false);
+  });
+});
diff --git a/server/routers.ts b/server/routers.ts
index 2bcea39..5e43d2f 100644
--- a/server/routers.ts
+++ b/server/routers.ts
@@ -1,5 +1,6 @@
 import { z } from "zod";
 import { COOKIE_NAME } from "@shared/const";
+import { BAP_MIN_QUALITY_SCORE, meetsBapQualityThreshold } from "@shared/bapEligibility";
 
 interface Condition {
   field: string;
@@ -499,8 +500,8 @@ export const appRouter = router({
         const hasService = !!invoice.serviceConcerne;
         const hasTypeAchat = !!invoice.typeAchat;
         const hasVentilation = !!invoice.ventilationComptable;
-        if (score < 100) {
-          throw new TRPCError({ code: "BAD_REQUEST", message: "Le score de qualité doit être à 100% pour valider" });
+        if (!meetsBapQualityThreshold(score)) {
+          throw new TRPCError({ code: "BAD_REQUEST", message: `Le score de qualité doit être au moins de ${BAP_MIN_QUALITY_SCORE}% pour valider` });
         }
         if (!isNotSubscription) {
           throw new TRPCError({ code: "BAD_REQUEST", message: "La facture est marquée comme abonnement" });
@@ -720,7 +721,7 @@ export const appRouter = router({
         const allInvoices = ctx.user.role === 'admin' ? await getAllInvoices() : await getInvoicesByUser(ctx.user.id);
         // Filtrer les factures éligibles (non déjà validées)
         const eligible = allInvoices.filter((inv: any) =>
-          (inv.qualityScore || 0) >= 100 &&
+          meetsBapQualityThreshold(inv.qualityScore) &&
           inv.isSubscription === 0 &&
           !!inv.serviceConcerne &&
           !!inv.typeAchat &&
diff --git a/shared/bapEligibility.ts b/shared/bapEligibility.ts
new file mode 100644
index 0000000..ca91b09
--- /dev/null
+++ b/shared/bapEligibility.ts
@@ -0,0 +1,10 @@
+/** Score minimal requis pour générer et valider un BAP. */
+export const BAP_MIN_QUALITY_SCORE = 90;
+
+/**
+ * Centralise le seuil BAP afin que l’interface et le serveur appliquent la
+ * même règle métier, y compris pour les scores nuls ou absents.
+ */
+export function meetsBapQualityThreshold(score: number | null | undefined): boolean {
+  return typeof score === "number" && Number.isFinite(score) && score >= BAP_MIN_QUALITY_SCORE;
+}
diff --git a/todo.md b/todo.md
index 65cf72d..bd10390 100644
--- a/todo.md
+++ b/todo.md
@@ -782,3 +782,8 @@
 - [x] Déployer et vérifier le filtre par action en recette
 - [x] Pousser la version validée vers Gitea production
 - [x] Déployer et vérifier le filtre par action en production
+
+## Seuil d’éligibilité BAP à 90 %
+- [x] Identifier les validations BAP fondées sur le score de qualité
+- [x] Abaisser le seuil de 100 % à 90 % pour les opérations BAP
+- [x] Ajouter les tests de seuil et valider TypeScript, tests et build