Yeah, by default all Pro and Ultra plans are unlimited requests with rate limits (burst rate limits and local rate limits; burst rate limits can be dipped into at any time for particularly bursty sessions but are slow to refill. Local rate limits refill fully every few hours).
If a user uses up both their local and burst limits; their options are:
- switch to cheaper models which have higher rate limits
- have a usage based price limit set and dip into usage based price (until the next rate limit reset)
- upgrade to an ultra plan which has 20x rate limits.