Gemini API Tier 1 project incorrectly enforced as Free Tier for Gemini 3.1 Flash Image

[Amit_Das1]

Hello Google AI Studio Support,

I believe I have found a quota/billing issue affecting my Gemini API project.

Project Information

• Project Name: Gemini Cbshopin Project

• Project ID: gen-lang-client-09873579..

• Project number: 6303003224..

• Billing Tier: Tier 1 (Postpay)

• API Keys created in: Google AI Studio

Problem

Text generation works correctly using Gemini models.

However, every request to the Gemini 3.1 Flash Image model fails with HTTP 429 RESOURCE_EXHAUSTED.

The response indicates that my project is being evaluated against Free Tier quotas even though the project is Tier 1.

Endpoint

POST https://generativelanguage.googleapis.com/v1beta/models/gemini-3.1-flash-image:generateContent

Error Returned

HTTP 429
RESOURCE_EXHAUSTED

Quota exceeded for metric:
generativelanguage.googleapis.com/generate_content_free_tier_requests

Quota ID:
GenerateRequestsPerDayPerProjectPerModel-FreeTier

limit: 0
model: gemini-3.1-flash-image

The response repeatedly reports:

• GenerateRequestsPerDayPerProjectPerModel-FreeTier

• GenerateRequestsPerMinutePerProjectPerModel-FreeTier

• GenerateContentInputTokensPerModelPerMinute-FreeTier

What I Verified

• Billing is active (Tier 1 Postpay).

• The API key belongs to this project.

• I generated a brand-new API key and received the same result.

• The request was tested both from my PHP application and directly using the Gemini REST API.

• Both methods return the identical 429 RESOURCE_EXHAUSTED response.

• The endpoint and payload follow the official Gemini API documentation.

Expected Behaviour

Since the project is Tier 1, image generation requests should use the project’s paid/Tier 1 quotas instead of Free Tier quotas.

Additional Observation

The AI Studio Rate Limits page shows image generation quotas for:

• Nano Banana 2 (Gemini 3.1 Flash Image)

• Nano Banana 2 Lite (Gemini 3.1 Flash Lite Image)

indicating that the project should have image generation quota available.

However, the API backend still reports:

GenerateRequestsPerDayPerProjectPerModel-FreeTier
limit: 0

This appears to be a mismatch between the project’s configured billing tier and the quota service enforcing requests.

Could you please investigate whether this project’s Gemini Image quota is incorrectly associated with the Free Tier?

Thank you.

[Payal_Sharma2]

Hi,
This happened because your project gen-lang-client-09873... is assigned Free Tier limits due to low historical billing activity on billing account 01318B-FE0E7D-30.... Text generation succeeded because Free Tier provides baseline text quotas, whereas gemini-3.1-flash-image has zero Free Tier quota.

Immediate steps to resolve:

• Option A (Add Prepaid Funds): Add prepaid funds or make an advance payment on billing account 01318B-FE0E7D-30... to establish immediate payment history.
• Option B (Link Existing Account): Attach a different active billing account that already has an established payment history to project gen-lang-client-09873....

[Amit_Das1]

Thank you for the clarification.

I have already added a prepaid balance of $10 to my billing account before testing the API.

However, my AI Studio Rate Limits page already shows Tier 1 quotas for image models (Nano Banana 2 / Gemini 3.1 Flash Image), while the API continues to enforce:

GenerateRequestsPerDayPerProjectPerModel-FreeTier (limit: 0)

Could you please clarify:

• How much payment history is required before image quotas are activated?

• Does a $10 prepaid balance not qualify?

• Is there a propagation delay after adding prepaid funds?

Can you verify whether my project gen-lang-client-09873… is correctly linked to the billing account and whether the image quotas have actually been enabled on the backend?