In the past, an API account was “pay as you go”, a phrase perhaps just to contrast your usage-based billing on the API from that of a ChatGPT subscription that is recurrent. Here’s that phrase showing even with monthly post-payment:
With virtually everyone being forced off of post-pay and needing to make full prepayment satisfactory for any usage job, and needing to meet higher levels of handing over cash in the past to activate higher “tier” limits and and have a chance at being offered newest models, the API service can barely be called “pay as you go” now, despite that text still in the user interface.
It is “Now pay minimum amounts of dollars, buying credits”. Credits which can then be used to fund individual API calls - until the credits self-expire in a year, or any OpenAI-manufactured account termination reason.
(FYI: You need to do your prepay credit check on OpenAI’s trustworthiness - instead of the other way around for a typical netX business invoice. You’re not truly loaning OpenAI money for a year though; they instantly convert cash into promises and disclaimers. The money is not coming back out to you, service or no service. )
OpenAI currently has two API pricing pages that both serve similar purposes answering about the same models and pricing.