diff --git a/open-sse/config/errorConfig.ts b/open-sse/config/errorConfig.ts
index 84c6df8bd4..3bcad8edcc 100644
--- a/open-sse/config/errorConfig.ts
+++ b/open-sse/config/errorConfig.ts
@@ -105,6 +105,18 @@ export const ERROR_RULES: ErrorRule[] = [
     backoff: true,
     reason: "rate_limit_exceeded",
   },
+  {
+    id: "hour_quota_exceeded",
+    text: "hour quota",
+    backoff: true,
+    reason: "quota_exhausted",
+  },
+  {
+    id: "quota_has_been_exceeded",
+    text: "quota has been exceeded",
+    backoff: true,
+    reason: "quota_exhausted",
+  },
   {
     id: "quota_exceeded",
     text: "quota exceeded",
diff --git a/open-sse/services/accountFallback.ts b/open-sse/services/accountFallback.ts
index 446b9510c1..bf6e06d3cd 100644
--- a/open-sse/services/accountFallback.ts
+++ b/open-sse/services/accountFallback.ts
@@ -755,6 +755,8 @@ export function classifyErrorText(errorText) {
     lower.includes("quota depleted") ||
     lower.includes("quota will reset") ||
     lower.includes("your quota will reset") ||
+    lower.includes("quota has been exceeded") ||
+    lower.includes("hour quota") ||
     lower.includes("billing")
   ) {
     return RateLimitReason.QUOTA_EXHAUSTED;
@@ -1038,7 +1040,9 @@ export function checkFallbackError(
       status === HTTP_STATUS.FORBIDDEN &&
       provider &&
       getProviderCategory(provider) === "apikey" &&
-      !errorStr.toLowerCase().includes("has not been used in project")
+      !errorStr.toLowerCase().includes("has not been used in project") &&
+      !errorStr.toLowerCase().includes("hour quota") &&
+      !errorStr.toLowerCase().includes("quota has been exceeded")
     ) {
       return buildRetryableFallback(RateLimitReason.AUTH_ERROR);
     }
diff --git a/tests/unit/account-fallback-service.test.ts b/tests/unit/account-fallback-service.test.ts
index 4d0d9e5a77..d3dac846d1 100644
--- a/tests/unit/account-fallback-service.test.ts
+++ b/tests/unit/account-fallback-service.test.ts
@@ -759,3 +759,58 @@ test("recordModelLockoutFailure uses regular backoff for non-quota reasons", ()
     clearModelLock("modelscope", "test-conn-modelscope-2", "qwen/Qwen2.5-Coder-32B-Instruct");
   }
 });
+
+// Test for hour quota related error messages
+test("checkFallbackError classifies hour quota errors correctly", () => {
+  // For OAuth providers (e.g., codex), hour quota errors should be QUOTA_EXHAUSTED
+  const result1 = checkFallbackError(
+    429,
+    "Coding Plan hour quota has been exceeded",
+    0,
+    null,
+    "codex"
+  );
+  assert.equal(result1.shouldFallback, true);
+  assert.equal(result1.reason, RateLimitReason.QUOTA_EXHAUSTED);
+
+  const result2 = checkFallbackError(429, "hour quota exceeded", 0, null, "codex");
+  assert.equal(result2.shouldFallback, true);
+  assert.equal(result2.reason, RateLimitReason.QUOTA_EXHAUSTED);
+
+  const result3 = checkFallbackError(429, "Your hour quota is exceeded", 0, null, "codex");
+  assert.equal(result3.shouldFallback, true);
+  assert.equal(result3.reason, RateLimitReason.QUOTA_EXHAUSTED);
+
+  const result4 = checkFallbackError(429, "hour quota depleted", 0, null, "codex");
+  assert.equal(result4.shouldFallback, true);
+  assert.equal(result4.reason, RateLimitReason.QUOTA_EXHAUSTED);
+
+  // For API-key providers with 402 status, hour quota errors should be QUOTA_EXHAUSTED
+  const result5 = checkFallbackError(402, "hour quota has been exceeded", 0, null, "openai");
+  assert.equal(result5.shouldFallback, true);
+  assert.equal(result5.reason, RateLimitReason.QUOTA_EXHAUSTED);
+
+  const result6 = checkFallbackError(
+    403,
+    "Coding Plan hour quota has been exceeded",
+    0,
+    null,
+    "openai"
+  );
+  assert.equal(result6.shouldFallback, true);
+  assert.equal(result6.reason, RateLimitReason.QUOTA_EXHAUSTED);
+});
+
+// Test for classifyErrorText function with hour quota
+test("classifyErrorText handles hour quota messages", () => {
+  const { classifyErrorText } = accountFallback;
+
+  assert.equal(
+    classifyErrorText("Coding Plan hour quota has been exceeded"),
+    RateLimitReason.QUOTA_EXHAUSTED
+  );
+  assert.equal(classifyErrorText("hour quota exceeded"), RateLimitReason.QUOTA_EXHAUSTED);
+  assert.equal(classifyErrorText("Your hour quota is exceeded"), RateLimitReason.QUOTA_EXHAUSTED);
+  assert.equal(classifyErrorText("hour quota has been exceeded"), RateLimitReason.QUOTA_EXHAUSTED);
+  assert.equal(classifyErrorText("quota has been exceeded"), RateLimitReason.QUOTA_EXHAUSTED);
+});