Tier 1 Postpay project returns 429 "prepayment credits are depleted" despite active linked billing — manual billing sync request

Gemini API
1

Hello Google team,

I’m requesting a manual billing sync and an investigation into a billing/quota
inconsistency on my project.

Project details:

  • Project ID: wakesong-79f8..
  • Project number: 9925219364..
  • Billing account: Active, with a valid payment method on file and linked to
    this project (the same account already pays for Cloud Functions usage on this
    project without issues)
  • AI Studio shows: Tier 1 · Postpay
  • Recorded Gemini API usage this period: none (calls are rejected before any
    usage registers)

What works:

  • API key authenticates correctly
  • models.list returns models normally
  • The API key is correctly restricted to the Gemini API

What fails:

  • Every generateContent call (model: gemini-2.0-flash) returns:
    429 RESOURCE_EXHAUSTED
    “Your prepayment credits are depleted. Please go to AI Studio at
    https://ai.studio/projects to manage your project and billing.”
    status: RESOURCE_EXHAUSTED

Additional context:

  • The project is on the paid tier with an active, linked Cloud billing account.
  • The Gemini billing page shows R$ 0.00 spend and “no usage data available”,
    yet every call is rejected with the prepayment-depleted message.
  • I am NOT on prepay — the project shows as Postpay. Generating a fresh API key
    did not resolve the issue.
  • The API key is linked to a service account
    (ais-gemini-key-…@9…iam.gserviceaccountcom), if relevant.
  • First occurrence: 2026-06-27.

This matches several other recently reported Tier 1 Postpay cases with the same
error. Could you please perform a manual billing sync for this project and
investigate why postpay calls are being rejected as prepayment-depleted?

Thank you.