Billing mismatch: Cloud Billing has active payment method but AI Studio shows "Error during billing setup" / no prepayment configured

Gemini API
,
1

Hello,

I’m unable to configure prepayment for the Gemini API, even though my Cloud Billing account already has an active, valid payment method on file.

Current state

  • Billing account ID: 007DC9-528AD4-9BE3.. (“My Billing Account”)
  • Project linked: GymCoach (gymcoach-4999..)
  • AI Studio Billing page shows: “Paid tier 1 · US$ 250 account level limit,” 1 project linked
  • Same page shows: “No prepayment method has been configured for this billing account. Prepayment is required for this billing account.”
  • Clicking “Set up prepayment” immediately shows a toast error: “Error during billing setup” — the flow never opens.

Payment method status (Cloud Console)

Checked directly at Billing → Forma de pagamento: there IS an active principal payment method (Mastercard ending 6978, valid through 04/31). So the Cloud Billing account is correctly funded/payable, but AI Studio’s prepay layer doesn’t recognize it.

What I already tried

  1. Verified payment method is active and not expired in Cloud Console.
  2. Tried opening the AI Studio billing setup flow multiple times — same “Error during billing setup” toast every time.
  3. Checked the billing account → project link (GymCoach is correctly linked, no “no billing account available” issue on that side).

Request

Could someone from the team check the sync between Cloud Billing and the AI Studio prepay balance for billing account 007DC9-528AD4-9BE3.. / project gymcoach-4999..? This looks like the same class of issue reported in other recent threads (e.g. “Billing mismatch: Gemini API 429 on Tier 1 (Prepay) while Cloud Billing has funds but AI Studio shows $0.00”).

Thank you!