How OpenAI's usage tier system actually works
OpenAI uses a dual-gate system: you must clear both a cumulative spend threshold AND a minimum number of days since your organization's first successful payment. Both gates must be satisfied simultaneously. You cannot skip the time gate by prepaying a large credit balance all at once — the clock starts on the date your first API charge clears, and you have to wait the minimum number of days regardless of how much you've spent.
The spend number that matters is cumulative lifetime API spend, not monthly recurring spend. A $5 credit top-up in Month 1 that you burn through counts toward your Tier 2 threshold even if you add no more credits for 60 days. OpenAI tracks this at the organization level, not the project or API key level. If you have multiple projects under one org, their spend aggregates toward the tier threshold.
Rate limit increases apply automatically when you cross a threshold — you do not need to submit a request or open a support ticket. The tier advancement is checked periodically (typically within 24 hours of crossing the threshold). If you are close to a threshold near the end of a billing period and expect to cross it, your limits will update on the next check cycle.
The community.openai.com forum has hundreds of threads where developers ask about tier advancement. The consistent answer from OpenAI staff: spend + time, no shortcuts, no exceptions for individual accounts. The only pathway to higher limits outside the tier system is a manual Enterprise rate limit increase, which requires contacting OpenAI sales.