Billing mismatch: Gemini API 429 on Tier 1 (Prepay) while Cloud Billing has funds but AI Studio shows $0.00

Google AI Studio
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1

Hi,

I’m encountering a billing inconsistency between Google Cloud Platform and Google AI Studio.

Gemini API returns:

429 “Your prepayment credits are depleted”

However:

  • The project is linked to a Cloud billing account
  • The billing account is active and has available funds in Google Cloud Console

In AI Studio:

  • The same Cloud Prepay account is visible
  • But its balance is shown as $0.00

So currently:

  • Cloud Billing → shows available funds
  • AI Studio → shows zero credits
  • Gemini API → fails with 429

Additional details:

  • In AI Studio, the billing account is shown as “Tier 1 · Prepay”
  • In Google Cloud Billing, the account is active and funded
  • The issue persists for more than 24 hours

I also tried the suggested workaround:

  • created a new project in Google Cloud Console
  • enabled the Gemini / Generative Language API
  • opened/imported that project in AI Studio
  • created a new API key

This did not help.

I still get:

429 “Your prepayment credits are depleted”

This looks like a synchronization issue between Cloud Billing and AI Studio.

I also found reports from other users who already tried new projects, new API keys, and even manual prepayment, but the issue still persisted. So this does not appear to be a simple project/key configuration problem.

Can someone from Google take a look?

2

I believe it’s because Google Ai Studio has its own billing format. After the new terms and conditions, the 250/300 credits (or rather, Google Cloud) cannot be used on generative API anymore.

3

These are prepaid funds that were added via a payment method (bank card).

4

Same billing mismatch issue, slightly different situation.

Gemini API returns:
429 “Your prepayment credits are depleted”

My setup:

  • Project: “Joshua limitless”
  • Tier 2 (despite spending well over Tier 3 thresholds)
  • Billing plan: Postpay (NOT Prepay)
  • Active credit: -COP 297,598 (Google owes me)
  • Last manual payment: April 9, COP 250,000
  • Made another manual payment today — went into Postpay bucket,
    API still returns 429

Key inconsistencies:

  1. I am on Postpay, but API says “prepayment credits depleted” —
    there is no Prepay section visible in my billing dashboard
  2. My billing account tier cap shows COP 7,336,550 (~$1,800 USD)
    which should qualify me for Tier 3, but I’m shown as Tier 2
  3. Billing page says “Balance is for both Gemini API service and
    Cloud services” — but the API disagrees
  4. No “Buy prepay credits” option is visible anywhere in my
    billing interface
  5. Under Projects, status shows “No available credits” despite
    the Postpay credit being available

What I’ve tried:

  • Generated new API key (same project) — same error
  • Raised spend cap to COP 200,000 — no effect
  • Added rate limit of COP 100,000 — no effect
  • Manual payment today — credit went to Postpay, API still blocked
  • Waited over 4 hours — no change

I suspect the March 23 billing changes created a split charging
cycle on my account that requires Prepay credits for Gemini API,
but my account was never given the option to purchase Prepay
credits — only Postpay payments are available.

My billing currency is COP (Colombian Pesos). Some of the tier cap
numbers suggest the system may be confusing COP with USD.

Can someone from Google investigate? This has been blocking API
access for over 12 hours.

Account email: j......@lapuerta.com.co
Project: Joshua limitless