The Unity AI assistant may show a "Not enough credits remaining" error even if credits are visible because each model (Ultra, Default, Lite) has a minimum credit threshold per request. Requests are blocked if the balance is below this threshold. To resolve this, switch to Unity Lite, review credit usage documentation, or replenish credits by waiting for a monthly refresh or purchasing a top-up. Unity Lite requires the fewest credits.
Symptoms
Even when credits are visible in your account, the AI assistant displays the following error:
"Not enough credits remaining. Credits refresh at the start of the month. You can also purchase a top-up."
Cause
Unity AI assistant models (Ultra / Default / Lite) each require a different minimum credit threshold per request. Even if credits remain in your account, requests will be blocked if the balance falls below the minimum threshold required by the selected model.
Resolution
- Switch to Unity Lite — Lite requires the lowest minimum credit threshold among the three modes, making it the most accessible option when your remaining credits are low.
- Review credit usage documentation — Check credit requirements for each model: https://docs.unity.com/en-us/ai/credits/credits-about
- Replenish credits — Wait for the monthly automatic refresh, or purchase a top-up if needed.
💡 Key takeaway: If you see "Not enough credits remaining" despite having credits available, your balance is below the minimum threshold for the currently selected model. Unity Lite is the mode that requires the fewest credits to operate.