OpenAI bills for two things that are easy to confuse, and telling them apart is the first step in identifying any charge.
A ChatGPT subscription is a fixed recurring amount on a consistent date. Same figure every month, regardless of how much you used it.
API usage is metered. You are billed for what you consumed, so the amount varies every month and the billing date may not be fixed. Developers using the API for a project can see charges swing considerably.
A variable OpenAI charge is almost always API usage. A fixed one is a subscription.
The tiers
| Product | Billing pattern |
|---|---|
| ChatGPT Plus | Fixed monthly, per individual |
| ChatGPT Pro | Fixed monthly, substantially higher |
| ChatGPT Team | Per seat, so the total changes when members are added or removed |
| API | Usage-based, variable, often billed when a threshold is reached |
Team plans catch people out because the charge scales with seats. Adding a colleague changes the monthly amount without any separate notification that reads like a price change.
Currency and VAT
OpenAI has historically priced in US dollars for many customers. If your subscription is billed in dollars, the sterling amount that reaches your statement varies month to month with the exchange rate, and your card may add a foreign transaction fee on top.
A subscription that is supposedly a fixed price but changes by small amounts each month is usually this rather than a pricing change. UK VAT treatment can also alter the total depending on whether the account is registered as a business.
Charges after cancelling
Cancelling a ChatGPT subscription stops the next renewal; access continues to the end of the paid period. API billing works differently: cancelling a subscription does not close an API account, and usage already incurred is still billed afterwards.
If you set up API access for a project, check the API billing settings separately and set a usage limit. An abandoned integration left running can continue generating charges indefinitely.
Where to look
- For subscriptions, open ChatGPT, then Settings, then Subscription to see plan and renewal date.
- For API charges, sign in to the OpenAI platform site and open the billing and usage pages, which itemise consumption.
- Set a hard usage limit on any API account you are not actively monitoring.
- Check whether you subscribed through an app store, in which case Apple or Google bills you and OpenAI cannot cancel it.