diff --git a/src/cliproxy/account-manager.ts b/src/cliproxy/account-manager.ts
index 57495035..b1044cdc 100644
--- a/src/cliproxy/account-manager.ts
+++ b/src/cliproxy/account-manager.ts
@@ -16,8 +16,8 @@ import { CLIPROXY_PROFILES } from '../auth/profile-detector';
 import { getCliproxyDir, getAuthDir } from './config-generator';
 import { PROVIDER_TYPE_VALUES } from './auth/auth-types';
 
-/** Account tier for quota management (free vs paid - no Pro/Ultra distinction needed) */
-export type AccountTier = 'free' | 'paid' | 'unknown';
+/** Account tier for quota management: ultra > pro > free */
+export type AccountTier = 'free' | 'pro' | 'ultra' | 'unknown';
 
 /**
  * Providers that typically have empty email in OAuth token files.
@@ -47,7 +47,7 @@ export interface AccountInfo {
   paused?: boolean;
   /** ISO timestamp when paused */
   pausedAt?: string;
-  /** Account tier: free or paid (Pro/Ultra combined) */
+  /** Account tier: ultra, pro, or free */
   tier?: AccountTier;
   /** GCP Project ID (Antigravity only) - read-only, fetched from auth token */
   projectId?: string;
diff --git a/src/cliproxy/model-catalog.ts b/src/cliproxy/model-catalog.ts
index 7f035350..80406bb9 100644
--- a/src/cliproxy/model-catalog.ts
+++ b/src/cliproxy/model-catalog.ts
@@ -36,8 +36,8 @@ export interface ModelEntry {
   id: string;
   /** Human-readable name for display */
   name: string;
-  /** Access tier indicator - 'paid' means requires paid Google account (not free tier) */
-  tier?: 'free' | 'paid';
+  /** Access tier indicator - 'ultra' for Claude, 'pro' for premium Gemini, 'free' for basic */
+  tier?: 'free' | 'pro' | 'ultra';
   /** Optional description for the model */
   description?: string;
   /** Model has known issues - show warning when selected */
@@ -119,7 +119,7 @@ export const MODEL_CATALOG: Partial<Record<CLIProxyProvider, ProviderCatalog>> =
       {
         id: 'gemini-3-pro-preview',
         name: 'Gemini 3 Pro',
-        tier: 'paid',
+        tier: 'pro',
         description: 'Latest model, requires paid Google account',
         thinking: { type: 'levels', levels: ['low', 'high'], dynamicAllowed: true },
       },
diff --git a/src/cliproxy/model-config.ts b/src/cliproxy/model-config.ts
index ddec180b..2da1cc63 100644
--- a/src/cliproxy/model-config.ts
+++ b/src/cliproxy/model-config.ts
@@ -51,8 +51,13 @@ export function getCurrentModel(
  * Format model entry for display in selection list
  */
 function formatModelOption(model: ModelEntry): string {
-  // Tier badge: clarify that "paid" means paid Google account (not free tier)
-  const tierBadge = model.tier === 'paid' ? color(' [Paid Tier]', 'warning') : '';
+  // Tier badge: ultra/pro indicate paid tiers
+  const tierBadge =
+    model.tier === 'ultra'
+      ? color(' [Ultra]', 'warning')
+      : model.tier === 'pro'
+        ? color(' [Pro]', 'warning')
+        : '';
   const brokenBadge = model.broken ? color(' [BROKEN]', 'error') : '';
   const deprecatedBadge = model.deprecated ? color(' [DEPRECATED]', 'warning') : '';
   return `${model.name}${tierBadge}${brokenBadge}${deprecatedBadge}`;
@@ -64,7 +69,12 @@ function formatModelOption(model: ModelEntry): string {
 function formatModelDetailed(model: ModelEntry, isCurrent: boolean): string {
   const marker = isCurrent ? color('>', 'success') : ' ';
   const name = isCurrent ? bold(model.name) : model.name;
-  const tierBadge = model.tier === 'paid' ? color(' [Paid Tier]', 'warning') : '';
+  const tierBadge =
+    model.tier === 'ultra'
+      ? color(' [Ultra]', 'warning')
+      : model.tier === 'pro'
+        ? color(' [Pro]', 'warning')
+        : '';
   const brokenBadge = model.broken ? color(' [BROKEN]', 'error') : '';
   const deprecatedBadge = model.deprecated ? color(' [DEPRECATED]', 'warning') : '';
   const desc = model.description ? dim(` - ${model.description}`) : '';
diff --git a/src/cliproxy/quota-fetcher.ts b/src/cliproxy/quota-fetcher.ts
index 9301d985..f65f9540 100644
--- a/src/cliproxy/quota-fetcher.ts
+++ b/src/cliproxy/quota-fetcher.ts
@@ -303,12 +303,13 @@ function readAuthData(provider: CLIProxyProvider, accountId: string): AuthData |
 
 /**
  * Map tier ID string to AccountTier type
- * Simplified: anything with 'pro' or 'ultra' = paid, 'free'/'legacy' = free
+ * Priority: ultra > pro > free
  */
 function mapTierString(tierStr: string | undefined): AccountTier {
   if (!tierStr) return 'unknown';
   const normalized = tierStr.toLowerCase();
-  if (normalized.includes('ultra') || normalized.includes('pro')) return 'paid';
+  if (normalized.includes('ultra')) return 'ultra';
+  if (normalized.includes('pro')) return 'pro';
   if (normalized.includes('free') || normalized.includes('legacy')) {
     return 'free';
   }
@@ -317,31 +318,6 @@ function mapTierString(tierStr: string | undefined): AccountTier {
   return 'unknown';
 }
 
-/**
- * Infer tier from model access patterns.
- * - Paid: Has access to Claude models OR premium Gemini models
- * - Free: Only basic models
- *
- * Claude models are Ultra-exclusive, premium Gemini indicates Pro/Ultra.
- * Both are "paid" tier for our purposes.
- */
-function inferTierFromModels(models: ModelQuota[]): AccountTier {
-  if (models.length === 0) return 'unknown';
-
-  // Check for Claude models (Ultra-exclusive) or premium Gemini (Pro/Ultra)
-  const hasPaidAccess = models.some((m) => {
-    const name = m.name.toLowerCase();
-    return (
-      name.includes('claude') ||
-      name.includes('gemini-3-pro') ||
-      name.includes('gemini-2.5-pro') ||
-      name.includes('gemini-pro-high')
-    );
-  });
-
-  return hasPaidAccess ? 'paid' : 'unknown';
-}
-
 /**
  * Get project ID and tier via loadCodeAssist endpoint
  * Uses allowedTiers array with isDefault=true (CLIProxyAPIPlus approach)
@@ -650,15 +626,14 @@ export async function fetchAccountQuota(
         refreshResult.accessToken,
         projectId as string
       );
-      // Determine tier: model access (Claude = Ultra) > API tier > fallback
+      // Determine tier from API response only (model inference is unreliable)
       if (retryResult.success) {
-        let finalTier = inferTierFromModels(retryResult.models);
-        if (finalTier === 'unknown') {
-          finalTier = apiTier !== 'unknown' ? apiTier : 'paid';
-        }
+        const finalTier = apiTier !== 'unknown' ? apiTier : 'unknown';
         retryResult.tier = finalTier;
         retryResult.accountId = accountId;
-        setAccountTier(provider, accountId, finalTier);
+        if (finalTier !== 'unknown') {
+          setAccountTier(provider, accountId, finalTier);
+        }
         if (verbose && retryResult.error) {
           console.log(`[!] Error: ${retryResult.error}`);
         }
@@ -667,15 +642,14 @@ export async function fetchAccountQuota(
     }
   }
 
-  // Determine tier: model access > API tier > fallback to paid
+  // Determine tier from API response only
   if (result.success) {
-    let finalTier = inferTierFromModels(result.models);
-    if (finalTier === 'unknown') {
-      finalTier = apiTier !== 'unknown' ? apiTier : 'paid';
-    }
+    const finalTier = apiTier !== 'unknown' ? apiTier : 'unknown';
     result.tier = finalTier;
     result.accountId = accountId;
-    setAccountTier(provider, accountId, finalTier);
+    if (finalTier !== 'unknown') {
+      setAccountTier(provider, accountId, finalTier);
+    }
   }
 
   if (verbose && result.error) {
diff --git a/src/cliproxy/quota-manager.ts b/src/cliproxy/quota-manager.ts
index 48e1bc12..577052fc 100644
--- a/src/cliproxy/quota-manager.ts
+++ b/src/cliproxy/quota-manager.ts
@@ -200,7 +200,7 @@ export async function findHealthyAccount(
   exclude: string[]
 ): Promise<{ id: string; tier: string; lastQuota: number } | null> {
   const config = loadOrCreateUnifiedConfig();
-  const tierPriority = config.quota_management?.auto?.tier_priority ?? ['paid'];
+  const tierPriority = config.quota_management?.auto?.tier_priority ?? ['ultra', 'pro', 'free'];
   const threshold = config.quota_management?.auto?.exhaustion_threshold ?? 5;
 
   const accounts = getProviderAccounts(provider);
@@ -225,7 +225,7 @@ export async function findHealthyAccount(
 
       return {
         id: account.id,
-        tier: account.tier || 'paid',
+        tier: account.tier || 'pro',
         lastQuota: avgQuota,
       };
     })
diff --git a/src/commands/cliproxy-command.ts b/src/commands/cliproxy-command.ts
index 55761a59..3e94af8d 100644
--- a/src/commands/cliproxy-command.ts
+++ b/src/commands/cliproxy-command.ts
@@ -152,7 +152,12 @@ function parseProfileArgs(args: string[]): CliproxyProfileArgs {
 }
 
 function formatModelOption(model: ModelEntry): string {
-  const tierBadge = model.tier === 'paid' ? color(' [Paid Tier]', 'warning') : '';
+  const tierBadge =
+    model.tier === 'ultra'
+      ? color(' [Ultra]', 'warning')
+      : model.tier === 'pro'
+        ? color(' [Pro]', 'warning')
+        : '';
   return `${model.name}${tierBadge}`;
 }
 
diff --git a/src/config/unified-config-types.ts b/src/config/unified-config-types.ts
index 130d6e0b..cf7e0f1f 100644
--- a/src/config/unified-config-types.ts
+++ b/src/config/unified-config-types.ts
@@ -409,7 +409,7 @@ export interface QuotaManagementConfig {
 export const DEFAULT_AUTO_QUOTA_CONFIG: AutoQuotaConfig = {
   preflight_check: true,
   exhaustion_threshold: 5,
-  tier_priority: ['paid'],
+  tier_priority: ['ultra', 'pro', 'free'],
   cooldown_minutes: 5,
 };
 
diff --git a/tests/unit/cliproxy/model-catalog.test.js b/tests/unit/cliproxy/model-catalog.test.js
index 0cd8beed..8b540bca 100644
--- a/tests/unit/cliproxy/model-catalog.test.js
+++ b/tests/unit/cliproxy/model-catalog.test.js
@@ -88,12 +88,12 @@ describe('Model Catalog', () => {
       assert.strictEqual(MODEL_CATALOG.gemini.defaultModel, 'gemini-2.5-pro');
     });
 
-    it('includes Gemini 3 Pro with paid tier', () => {
+    it('includes Gemini 3 Pro with pro tier', () => {
       const { MODEL_CATALOG } = modelCatalog;
       const gem3 = MODEL_CATALOG.gemini.models.find((m) => m.id === 'gemini-3-pro-preview');
       assert(gem3, 'Should include Gemini 3 Pro');
       assert.strictEqual(gem3.name, 'Gemini 3 Pro');
-      assert.strictEqual(gem3.tier, 'paid');
+      assert.strictEqual(gem3.tier, 'pro');
     });
 
     it('includes Gemini 2.5 Pro without tier (free)', () => {
@@ -197,7 +197,7 @@ describe('Model Catalog', () => {
           assert(typeof model.name === 'string', `Model name should be string`);
           // tier is optional
           if (model.tier !== undefined) {
-            assert(['free', 'paid'].includes(model.tier), `Invalid tier: ${model.tier}`);
+            assert(['free', 'pro', 'ultra'].includes(model.tier), `Invalid tier: ${model.tier}`);
           }
         }
       }