Gemini API errors with exhausted resources

Gemini API returns HTTP 429 RESOURCE_EXHAUSTED — “Your prepayment credits are depleted” — on every generateContent image request (gemini-3-pro-image, gemini-2.5-flash-image). I prepaid 200 BRL ($35) but AI Studio shows a $0.00 prepay balance. The API key authenticates fine (models.list returns 54 models); only paid generation fails. My actual usage this period is ~$7, far below the prepaid amount. The key value starts with AQ. rather than AIza. Why is the prepay balance reading $0.00 / not syncing from my funded billing account, and how do I link the funded billing account to the project this key uses?

Hi

Can you DM me your project ID and cloud billing ID ?

Hello, here is the information you requested. Thank you for the aid.

Billing ID: 01516D-A8C020-2E3A..
Project: gen-lang-client-0160235…

I can also provide invoices from my bank account.

Me too i have the same problem

I am facing the same problem

DM’ed for more details

It was working for me until a few hours ago. It was using my GCP credits now it is asking to prepay and buy credits. Have been using this for the past 6 months.