diff --git a/changelog.d/fixes/12744-free-predicate-guard.md b/changelog.d/fixes/12744-free-predicate-guard.md
new file mode 100644
index 0000000000..a0f979a149
--- /dev/null
+++ b/changelog.d/fixes/12744-free-predicate-guard.md
@@ -0,0 +1 @@
+- **fix(models):** stop treating provider-supplied `isFree:true`/`:free`/`0/0` flags as trusted unless the provider has a documented free tier — only the shipped free-tier catalog decides otherwise; fetched `isFree:true` trusted only for a free-tier provider, custom `isFree:true` via a trusted path ([#12744](https://github.com/diegosouzapw/OmniRoute/pull/12744)) — thanks @maxmad64bis
diff --git a/open-sse/services/autoCombo/paidModelFilter.ts b/open-sse/services/autoCombo/paidModelFilter.ts
index d50014021c..cc9e82e050 100644
--- a/open-sse/services/autoCombo/paidModelFilter.ts
+++ b/open-sse/services/autoCombo/paidModelFilter.ts
@@ -11,7 +11,7 @@
  * Kept as a pure, dependency-light function so the filter is unit-testable in
  * isolation without seeding the DB-backed virtual factory.
  */
-import { isFreeModel, providerHasFreeModels } from "@/shared/utils/freeModels";
+import { isFreeForProvider } from "@/shared/utils/freeModels";
 
 interface PaidFilterCandidate {
   provider: string;
@@ -22,10 +22,7 @@ interface PaidFilterCandidate {
  * selected model itself qualifies as free — mirrors `shouldHidePaid` in
  * `src/app/api/v1/models/catalog.ts`. */
 function isFreeCandidate(candidate: PaidFilterCandidate): boolean {
-  return (
-    providerHasFreeModels(candidate.provider) &&
-    isFreeModel(candidate.provider, { id: candidate.model })
-  );
+  return isFreeForProvider(candidate.provider, { id: candidate.model });
 }
 
 /**
diff --git a/src/app/api/models/openrouter-catalog/route.ts b/src/app/api/models/openrouter-catalog/route.ts
index dcb8656cd1..058c72939d 100644
--- a/src/app/api/models/openrouter-catalog/route.ts
+++ b/src/app/api/models/openrouter-catalog/route.ts
@@ -10,7 +10,7 @@ import { NextRequest, NextResponse } from "next/server";
 import { isAuthenticated } from "@/shared/utils/apiAuth";
 import { getOpenRouterCatalog, refreshOpenRouterCatalog } from "@/lib/catalog/openrouterCatalog";
 import { getSettings } from "@/lib/db/settings";
-import { isFreeModel } from "@/shared/utils/freeModels";
+import { isFreeForProvider } from "@/shared/utils/freeModels";
 
 export async function GET(req: NextRequest) {
   // Require authentication (dashboard/API key)
@@ -29,7 +29,9 @@ export async function GET(req: NextRequest) {
     hidePaid = settings?.hidePaidModels === true;
   } catch {}
   const applyFilter = <T extends { id?: string }>(data: T[]): T[] =>
-    hidePaid ? data.filter((m) => isFreeModel("or", m as { id: string; pricing?: unknown })) : data;
+    hidePaid
+      ? data.filter((m) => isFreeForProvider("openrouter", m as { id: string; pricing?: unknown }))
+      : data;
 
   const forceRefresh = req.nextUrl.searchParams.get("refresh") === "true";
 
diff --git a/src/app/api/v1/models/catalog.ts b/src/app/api/v1/models/catalog.ts
index 3e60e8bea2..075f7c2782 100644
--- a/src/app/api/v1/models/catalog.ts
+++ b/src/app/api/v1/models/catalog.ts
@@ -122,7 +122,7 @@ import {
 } from "./catalogRequest";
 import { incrementCcDiscoveryHitCount } from "@/lib/db/ccDiscoveryMetrics";
 import { isUnifiedChatSourceModelSelectable } from "./catalogModelPolicy";
-import { isFreeModel } from "@/shared/utils/freeModels";
+import { isFreeForProvider } from "@/shared/utils/freeModels";
 import { isModelExposureAllowed } from "@/shared/utils/modelExposureList";
 import { isCodexDiscoveryModelExcluded } from "@/shared/services/codexDiscoveryPolicy";
 import { buildErrorBody } from "@omniroute/open-sse/utils/error";
@@ -350,11 +350,9 @@ async function buildUnifiedModelsResponseCore(
     ): boolean => {
       if (!hidePaid) return false;
       const provider = aliasToProviderId[providerKey] || providerKey;
-      // isFree:true is the first door — custom row kept even when its provider is outside FREE_MODEL_BUDGETS.
-      if (isFreeModel(provider, { id: modelId, pricing: pricing as any, isFree })) return false;
-      // hidePaid is on and model is non-free → hidden. No need to consult FREE_MODEL_BUDGETS
-      // separately: paid on a free-capable provider stays hidden, free on a non-budget provider
-      // already returned above.
+      // fetched: free only when provider has a documented free tier — catalog hit or guarded heuristics (`:free`/`0`/`isFree:true`); fetched isFree:true not trusted alone
+      if (isFreeForProvider(provider, { id: modelId, pricing: pricing as any, isFree }))
+        return false;
       return true;
     };
     // #11481: opt-in explicit model exposure allow/deny list — same call sites
@@ -1659,10 +1657,10 @@ async function buildUnifiedModelsResponseCore(
           if (model.isHidden === true) continue;
           if (isModelHiddenBulk(providerId, modelId, canonicalProviderId)) continue;
           if (isExcludedByProviderConnections(canonicalProviderId, modelId)) continue;
-          // #6328: apply hidePaidModels to user-defined custom rows too.
-          // Custom entries do not carry pricing, so shouldHidePaid() decides
-          // via FREE_MODEL_IDS_BY_PROVIDER — matches synced/PROVIDER_MODELS.
+          // #6328: apply hidePaidModels to user-defined custom rows too. A local custom
+          // row flagged isFree:true stays trusted, even outside the free-tier catalog.
           if (
+            (model as { isFree?: unknown }).isFree !== true &&
             shouldHidePaid(
               canonicalProviderId,
               modelId,
diff --git a/src/shared/utils/freeModels.ts b/src/shared/utils/freeModels.ts
index 5f1f1c4a63..279e8cc295 100644
--- a/src/shared/utils/freeModels.ts
+++ b/src/shared/utils/freeModels.ts
@@ -29,10 +29,10 @@ import { AI_MODELS } from "@/shared/constants/models";
  * import modal's preview disagree with the import route that runs on click.
  *
  * A provider is considered to "have free models" when it appears in the
- * documented free-tier catalog (`FREE_MODEL_BUDGETS`). A single model is
- * considered free when its id carries the OpenRouter-style `:free` suffix, when
- * both its prompt and completion prices are zero, or when its id is listed as a
- * free model for that provider in the catalog.
+ * documented free-tier catalog (`FREE_MODEL_BUDGETS`). A single model is considered free when — for a provider with a documented
+ * free tier — its id carries the OpenRouter-style `:free` suffix or both its
+ * prompt and completion prices are zero (guarded heuristics), or when its id
+ * is listed as a free model for that provider in the shipped catalog.
  *
  * The catalog also records the regime of every entry via `freeType`
  * (`FreeModelFreeType`). A regime can retire a free tier behind a paid key
@@ -84,21 +84,34 @@ export interface FreeModelCandidate {
   isFree?: boolean;
 }
 
-/** Whether a single fetched model qualifies as free for the given provider (id or alias). */
-export function isFreeModel(provider: string, model: FreeModelCandidate): boolean {
+/** Shipped-catalog entry for this provider (id or alias): trusted on its own. */
+function isCatalogFreeModel(provider: string, modelId: unknown): boolean {
+  if (typeof modelId !== "string") return false;
+  return (
+    FREE_MODEL_IDS_BY_PROVIDER.get(provider)?.has(modelId) === true ||
+    FREE_MODEL_IDS_BY_PROVIDER.get(resolveProviderId(provider))?.has(modelId) === true
+  );
+}
+
+/** Payload-supplied free signals: `isFree:true`, a `:free` id suffix, or zero prices. */
+function hasPayloadFreeSignal(model: FreeModelCandidate): boolean {
   if (model.isFree === true) return true;
   if (typeof model.id === "string" && model.id.endsWith(":free")) return true;
-  if (isZeroPrice(model.pricing?.prompt) && isZeroPrice(model.pricing?.completion)) return true;
-  if (typeof model.id === "string") {
-    const canonical = resolveProviderId(provider);
-    if (
-      FREE_MODEL_IDS_BY_PROVIDER.get(provider)?.has(model.id) ||
-      FREE_MODEL_IDS_BY_PROVIDER.get(canonical)?.has(model.id)
-    ) {
-      return true;
-    }
-  }
-  return false;
+  return isZeroPrice(model.pricing?.prompt) && isZeroPrice(model.pricing?.completion);
+}
+
+/**
+ * Whether a single fetched model qualifies as free for the given provider (id or alias): a
+ * shipped-catalog entry, or a payload signal on a provider with a documented free tier.
+ */
+export function isFreeModel(provider: string, model: FreeModelCandidate): boolean {
+  if (isCatalogFreeModel(provider, model.id)) return true;
+  return providerHasFreeModels(provider) && hasPayloadFreeSignal(model);
+}
+
+/** Reusable free predicate for fetched payloads — provider must have a documented free tier. */
+export function isFreeForProvider(provider: string, model: FreeModelCandidate): boolean {
+  return providerHasFreeModels(provider) && isFreeModel(provider, model);
 }
 
 export interface SelectModelsForImportResult<T extends FreeModelCandidate> {
@@ -191,7 +204,7 @@ export function matchesOnlyPaidModels(pattern: string): boolean {
     const fullId = `${m.provider}/${m.model}`;
     if (!regex.test(fullId)) continue;
     matched = true;
-    if (isFreeModel(m.provider, { id: m.model })) return false;
+    if (isFreeForProvider(m.provider, { id: m.model })) return false;
   }
   return matched;
 }
diff --git a/tests/unit/free-models-isfree.test.ts b/tests/unit/free-models-isfree.test.ts
index 53217ace47..775df3f778 100644
--- a/tests/unit/free-models-isfree.test.ts
+++ b/tests/unit/free-models-isfree.test.ts
@@ -3,10 +3,12 @@ import assert from "node:assert/strict";
 import { isFreeModel, providerHasFreeModels } from "../../src/shared/utils/freeModels.ts";
 
 describe("isFreeModel isFree opt-in", () => {
-  it("isFree:true → free even without :free/pricing/catalog", () => {
-    assert.equal(isFreeModel("any", { id: "x", isFree: true }), true);
-    assert.equal(isFreeModel("openai", { id: "gpt-4o", isFree: true }), true);
-    assert.equal(isFreeModel("local", { id: "my-model", isFree: true }), true);
+  it("isFree:true fetched → free only for a provider with a documented free tier", async () => {
+    const { FREE_MODEL_BUDGETS } = await import("@omniroute/open-sse/config/freeModelCatalog");
+    const freeProvider = FREE_MODEL_BUDGETS[0].provider;
+    assert.equal(isFreeModel("any", { id: "x", isFree: true }), false);
+    assert.equal(isFreeModel("local", { id: "my-model", isFree: true }), false);
+    assert.equal(isFreeModel(freeProvider, { id: "x", isFree: true }), true);
   });
   it("isFree:false/null/undefined/1/'true' → not free (strict ===true)", () => {
     const junk: unknown[] = [false, null, undefined, 1, "true"];
@@ -22,9 +24,42 @@ describe("isFreeModel isFree opt-in", () => {
     assert.equal(providerHasFreeModels("local"), false);
     assert.equal(providerHasFreeModels("openai"), providerHasFreeModels("openai"));
   });
-  it(":free and pricing 0 still work when isFree absent", () => {
-    assert.equal(isFreeModel("any", { id: "foo:free" }), true);
-    assert.equal(isFreeModel("any", { id: "foo", pricing: { prompt: 0, completion: 0 } }), true);
+  it(":free and pricing 0 still work when isFree absent — only for free-tier providers", async () => {
+    const { FREE_MODEL_BUDGETS } = await import("@omniroute/open-sse/config/freeModelCatalog");
+    const freeProvider = FREE_MODEL_BUDGETS[0].provider;
+    assert.equal(isFreeModel("any", { id: "foo:free" }), false);
+    assert.equal(isFreeModel("local", { id: "foo", pricing: { prompt: 0, completion: 0 } }), false);
+    assert.equal(isFreeModel(freeProvider, { id: "foo:free" }), true);
+    assert.equal(
+      isFreeModel(freeProvider, { id: "foo", pricing: { prompt: 0, completion: 0 } }),
+      true
+    );
     assert.equal(isFreeModel("any", { id: "foo", pricing: { prompt: 0, completion: 1 } }), false);
   });
+  it("selectModelsForImport matches isFreeForProvider on every catalogued free model", async () => {
+    // FREE_MODEL_IDS_BY_PROVIDER is module-private, so rebuild (provider, id) pairs from the
+    // exported FREE_MODEL_BUDGETS: every budgeted provider has a documented free tier.
+    const { FREE_MODEL_BUDGETS } = await import("@omniroute/open-sse/config/freeModelCatalog");
+    const { selectModelsForImport, isFreeForProvider } =
+      await import("../../src/shared/utils/freeModels.ts");
+    for (const { provider } of FREE_MODEL_BUDGETS) {
+      const m = { id: `${provider}/probe-lock`, pricing: { prompt: 0, completion: 0 } };
+      const expected = isFreeForProvider(provider, m);
+      const { models } = selectModelsForImport(provider, [m], true);
+      assert.equal(models.length, expected ? 1 : 0, `${provider}/probe-lock`);
+    }
+  });
+  it("selectModelsForImport drops zero-price models on providers without documented free tier", async () => {
+    // "local" has no documented free tier, so its zero-price model is not free.
+    const { selectModelsForImport, providerHasFreeModels } =
+      await import("../../src/shared/utils/freeModels.ts");
+    assert.equal(providerHasFreeModels("local"), false);
+    const { models, freeFilterEmpty } = selectModelsForImport(
+      "local",
+      [{ id: "local/x", pricing: { prompt: 0, completion: 0 } }],
+      true
+    );
+    assert.deepEqual(models, []);
+    assert.equal(freeFilterEmpty, true);
+  });
 });