Subject: Gemini API — all models return "no longer available to new users" (404) despite active billing

Google AI Studio
1

Subject: Gemini API — all models return “no longer available to new users” (404) despite active billing

I have active billing set up on my Google AI Studio project (Tier 1, Prepay), and the Rate Limit dashboard shows my project correctly recognized with usage quotas (e.g. Gemini 3 Flash: 9/1K RPM). However, every model I try to call via the Gemini API — including gemini-1.5-pro, gemini-2.5-pro, gemini-2.0-flash, and gemini-2.5-flash — returns the same error:

{
  "error": {
    "code": 404,
    "message": "This model models/[MODEL_NAME] is no longer available to new users. Please update your code to use a newer model...",
    "status": "NOT_FOUND"
  }
}

I’ve confirmed this with a direct curl request (not through any third-party tool), using multiple different API keys created across different projects in my account, all with the same result. The models do appear in the ListModels response for my key, but calling generateContent on any of them fails with this “new users” message.

Given that my project has active billing configured, I don’t understand why my account is being treated as a “new user” without access to any current-generation model. Could you help clarify:

  1. Why is my account/project flagged this way despite active billing?
  2. What is the correct way to resolve this and gain access to current models (e.g. gemini-2.5-flash, gemini-2.5-pro)?

Since I have not been able to successfully use the API at all despite the active paid tier, I would also like to request a refund for the billing period during which I had no working access to the service.

Project number: 925292091.. (also tested with project 22007286..)

Thank you for your help.