OpenAI API credits are prepaid funds you buy before using the API, and your balance goes down as you use it. As of Nov 2026 the minimum purchase is $5, the default is $10, auto-reload is switched on by default, and purchased credits expire after 1 year.
Every new API account uses prepaid billing, so credits are the first thing you'll meet after you start with the OpenAI API. They're not the same as the credits on a ChatGPT plan, which I cover in my ChatGPT credits explainer. This page is only about the API balance.
How prepaid billing works
OpenAI's Help Center describes it plainly. You buy credits, and your credit balance decreases as you use the API. If your account has free credits, those are used before purchased credits. If you're already on monthly billing, you can still buy credits in advance, and they offset your monthly invoice.
One detail matters for anyone running a business. API access may not stop the instant your credits run out. Usage processed during that delay shows up as a negative balance, which is taken off your next purchase. OpenAI's own advice is not to rely on the prepaid balance as an instant spending cut-off.
Buying your first credits, step by step
You'll need permission to manage billing for the API organisation you're funding. Then, as of Nov 2026:
- Go to that organisation's API billing overview.
- Select Add payment details and complete the payment step.
- Choose your first purchase amount. The minimum is $5 and the default is $10.
- Look at Use auto-reload before you confirm. It's on by default. Turn it off if you don't want automatic purchases.
- If you keep auto-reload on, set the balance threshold, the balance to restore to, and an optional monthly reload limit.
- Confirm the purchase, then allow a few minutes for the balance to update.
If the balance still looks wrong after a few minutes, check the billing overview for the organisation you funded, since an earlier negative balance is deducted from your purchase. If it still doesn't match, contact Support with the organisation and purchase reference before buying again. That last line saves people from paying twice.
Auto-reload is on by default, so check it
Auto recharge adds credits whenever your balance falls below your threshold. The minimum recharge amount is $5, and your trust tier, which is based on your usage and payment history, decides the maximum recharge and the maximum balance your account can hold.
The optional monthly recharge limit caps automatic purchases only. Manual purchases don't count toward it. If a recharge would go over the remaining limit, only the remaining amount may be added, as long as it meets the minimum. And here's the bit people misread: a recharge limit isn't an API usage limit. It controls how much gets bought automatically, not how much of your existing balance can be spent.
Expiry and refunds
Purchased credits expire after 1 year, and OpenAI can't extend the expiry date of purchased credits or credit grants. Credits are non-refundable unless the law or a contract requires it, or an approved exception applies. Unused credits may qualify for a refund for a verified billing error, confirmed unauthorised activity, a confirmed OpenAI service failure or an incorrect account restriction. Credits you've already used may qualify only for confirmed unauthorised use or a verified billing correction. If you think an exception applies, you ask OpenAI Support for a review. If your refund question is about a ChatGPT subscription rather than the API, that's a different process, covered in my ChatGPT refund guide.
Two more cases from the Help Center. If a payment is disputed or refunded, credits equal to that amount are removed. If an automatic recharge payment fails, you get an email, and usage stops once the balance is exhausted.
When requests start failing: the four error codes
OpenAI says to check the error code in the API response before you change anything. A billing error may still show the broader type insufficient_quota, so look at the code itself:
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| Error code | What it means | What to do |
|---|---|---|
| credit_balance_exhausted | Your organisation has no prepaid credits left | Add credits to your API balance |
| organization_spend_limit_exceeded | Your organisation hit a hard spend limit you configured | Review the organisation's spend controls |
| project_spend_limit_exceeded | One project hit its own hard spend limit | Review that project's spend controls |
| organization_usage_limit_exceeded | Your organisation reached its OpenAI-assigned usage limit | Review your approved limit and options for an increase |
Retrying won't fix any of these. And a positive balance doesn't mean every request is safe: rate limits, your approved monthly usage limit and any spend limits all sit separately from your credits.
Build, Launch and Grow: the usage tiers
Paid API usage tiers are called Build, Launch and Grow. Your organisation moves up automatically when its total credit purchases reach $5, $100 and $500 respectively, and higher tiers generally come with higher rate limits. Older paid organisations were moved across without paying anything extra: Tiers 1 and 2 became Build, Tiers 3 and 4 became Launch, and Tier 5 became Grow. Check your organisation's Limits page for your own tier and limits, as of Nov 2026.
How I'd set up a small business account
I'd buy the minimum, turn auto-reload off until I trust the usage, and set a hard spend limit on the organisation. Spend alerts only send notifications, while a hard limit can stop requests when tracked spend reaches the amount you set. Skip buying a big balance up front, because credits expire after a year and you can't get unused ones back without an approved exception. If you'd rather compare other providers first, my roundup of OpenAI API alternatives is a good place to start.
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Frequently asked questions
What is the minimum OpenAI API credit purchase?
As of Nov 2026 the minimum purchase is $5 and the default amount is $10. The minimum automatic recharge is also $5.
Do OpenAI API credits expire?
Yes. Purchased credits expire after 1 year, and OpenAI can't extend the expiry date.
Can I get a refund on OpenAI API credits?
Credits are non-refundable unless law or contract requires it or an approved exception applies, such as a verified billing error or confirmed unauthorised activity.
Is auto-reload on by default?
Yes. Use auto-reload is turned on by default during setup. Turn it off before confirming if you don't want automatic purchases.
What does credit_balance_exhausted mean?
It means your organisation has no prepaid credits left. Add credits in your API billing overview and allow a few minutes for the balance to update.
