Gemini API stuck on free-tier 429 despite confirmed Tier 1 Prepay billing (3+ days)

Gemini API
1

Project: gen-lang-client-0914656621

My billing account (My Billing Account 1, ID 010DCF-6E3D95-DA5C..) was
upgraded from Free Trial to a Paid account on Sep 7, 2026 (confirmed in
Cloud Billing Console account details). It shows Tier 1 Prepay status with
a real, non-trial credit balance of 500,000 VND (charged via Visa card,
confirmed by my bank). The ai.dev/rate-limit dashboard confirms Tier 1 for
this project (500 RPM / 2,000 RPD for Nano Banana / gemini-2.5-flash-image).

Despite all of this, every generateContent call to gemini-2.5-flash-image
still returns 429 RESOURCE_EXHAUSTED with free-tier quota (limit: 0),
continuously for over 3 days now:

Endpoint: POST https://generativelanguage.googleapis.com/v1beta/models/gemini-2.5-flash-image:generateContent
Body: {“contents”: [{“parts”: [{“text”: “…”}]}], “generationConfig”: {“responseModalities”: [“IMAGE”]}}

Error:
{
“error”: {
“code”: 429,
“message”: “…Quota exceeded for metric: generativelanguage.googleapis.com/generate_content_free_tier_requests, limit: 0, model: gemini-2.5-flash-preview-image…”,
“status”: “RESOURCE_EXHAUSTED”
}
}

I opened a Google Cloud Billing support case (#75232607) which was closed
with a generic answer and redirected to “technical team,” but my current
support plan doesn’t allow creating a Technical case for this product. Has
anyone else hit this billing/quota sync bug, or does a Google team member
here have visibility into why this project’s paid tier isn’t being
recognized by the quota enforcement layer?

Thanks.

2

Hello @H_ng_H_nh_V_ng_Th ,

If you’re receiving 429’s and have checked no rate limit was breached for the period, please add your details to this form & we’ll check it out.

3

Hello. How can some one request help in the case where a spend limit was reached in the current billing period, but have since met all requirements for a Tier increase?

Thank you.