Gemini API Free Tier returns 403 PERMISSION_DENIED — Project denied access

Gemini API
1

Hello,

I am developing a forestry measurement application called Lemu Forest Measure and I am trying to use the Gemini Developer API for server-side voice interpretation and structured data extraction during development.

I would like to use the Gemini API Free Tier for development and testing. I do not want to enable billing/Paid Tier at this stage.

My Google AI Studio project is:

Project: Default Gemini Project
Project ID: gen-lang-client-06685504..
Project number: 1765705461..
Billing tier shown in Google AI Studio: Free Tier

I created Gemini API keys through Google AI Studio and tested the API directly using REST/cURL, independently of my application.

A request to gemini-2.5-flash reached the API but returned a 404 explaining that this model is no longer available to new users and recommending a newer model.

I then tested currently available models, including gemini-3.8-flash, and received:

403 PERMISSION_DENIED
Your project has been denied access. Please contact support.

To rule out a problem with the original project or API key configuration, I also created a completely new Google Cloud project under our corporate Google Workspace organization:

Project: Lemu Forest Measure
Project ID: lemu-forest-measure

For this project I:

  • Enabled the Gemini API (generativelanguage.googleapis.com)
  • Created a dedicated service account: lemu-gemini@lemu-forest-measure.iam.gserviceaccount.com
  • Created a new API key linked to that service account
  • Restricted the API key specifically to the Gemini API
  • Tested the API directly through REST/cURL, outside our application

The new project returned the same error:

403 PERMISSION_DENIED
Your project has been denied access. Please contact support.

I imported the new project into Google AI Studio as an additional diagnostic step. AI Studio marks this second project as Restricted and asks me to configure billing.

However, my original Default Gemini Project is explicitly shown as Free Tier in Google AI Studio, and it still returns the same 403 when calling the Gemini API.

Could you please review why my Free Tier project is being denied Gemini API access, and whether this restriction can be removed without enabling billing/Paid Tier?

This is a legitimate development/testing use case and no production traffic is currently being sent.

I have also enabled 2-Step Verification on the Google account.

Thank you.

2

Hello @Matias_Morales ,

Getting a 403 API error response and / or seeing “Unavailable” next to your project in AI audio indicates a flag has been placed on your account. To proceed:

  1. If you’re on the free tier with no billing attached, please try the below steps:

  2. Check Model Availability & Rate Limits:

    • Ensure that the model you are requesting is available on your current plan. For example, not all models are available on the free tier. You can verify model availability, quotas, and limits on the AI Studio Rate Limit dashboard.

  3. Ensure you have completed age verification by navigating to Google Account Age Verification and verifying date of birth in Google Account Personal Info.

  4. Complete Phone Verification and turn on 2-Step Verification (2SV) on the Google Account associated with your project.

  5. Once age, phone and 2sv are configured, retry your request or create a new API key in Google AI Studio.

  6. If completing these steps still does not restore access (or if using a model requiring a paid tier), you might want to consider adding prepayment credits directly in Google AI Studio and/ or attaching a Google Cloud Billing account in the Google Cloud Console. Please note this will mean you lose your free tier quota.

3

Hello, thank you for your response.

I completed all the suggested verification steps:

  • Age verification completed
  • Phone verification completed
  • 2-Step Verification enabled
  • Checked model availability and rate limits
  • Created a new API key in Google AI Studio

I also corrected and verified that my application is sending the API key correctly using the x-goog-api-key header.

The error has now changed to:

403 PERMISSION_DENIED
"Your project has been denied access. Please contact support."

The affected project is:
Lemu Forest Measure
Project ID: lemu-forest-measure

Google AI Studio also shows API access as restricted/unavailable.

Could you please perform a manual review of my account/project and let me know why access has been denied or restore Gemini API access if this is a false positive?

Thank you.

4

Hello @Matias_Morales ,

It seems like your projects are flagged by automated account security checks. To unblock this error, you should consider upgrading to a paid plan. You could add prepayment credits directly in Google AI Studio and/ or by attaching an active billing account in the Google Cloud Console.