Ran out of Codex? I did too.
I started asking the same questions you probably are: What do the limits mean? Do credits roll over? Is Pro worth it? Can a referral help? These are the answers I found, checked against OpenAI's current documentation.
See the answersStart with the problem you are having.
Do unused ChatGPT credits roll over after my Codex weekly reset?
Yes. Purchased ChatGPT usage credits remain available after your included Codex allowance resets, until the credits expire.
How many hours of Codex work can 500 credits buy?
There is no fixed hours-to-credits conversion. Here is a practical way to estimate what 500 Codex credits may buy.
Why is my Codex weekly limit at 0% when my 5-hour limit still has usage left?
Codex and Work can have more than one usage window. Hitting the weekly allowance can block new work even when the shorter window still has room.
What is a banked Codex reset, and what happens when I use it?
A banked Codex reset is a saved one-time usage-limit reset. It is not purchased credit.
Should I buy ChatGPT credits or an instant Codex reset?
Credits and instant resets solve the same immediate problem in different ways. One adds a reserve balance; the other pulls your weekly allowance forward.
Do ChatGPT Free and Go include Codex?
Yes. Codex is included across ChatGPT plans, including Free and Go, but the available models, usage and cloud features differ.
ChatGPT Plus vs Pro for Codex and Work: when does Pro make sense?
Plus already includes expanded Codex and Work access. Pro adds longer sessions and higher usage tiers, but costs substantially more.
Are ChatGPT usage credits the same as OpenAI API credits?
No. Credits bought for ChatGPT flexible usage are separate from API billing.
How do ChatGPT Desktop referral credit promotions work?
Eligible users may receive credits or other usage benefits after a referred person accepts an official invite, qualifies and completes the required action.
Can an existing ChatGPT user qualify for a ChatGPT Desktop referral?
Sometimes. Eligibility depends on the specific referral offer.
Do ChatGPT referral rewards expire?
They may. The expiration rule depends on the specific referral offer and reward type.
What happens when my Codex weekly limit resets?
Your included Work/Codex allowance refreshes for the new usage window. Purchased credits remain a separate fallback balance.
Can I buy Codex credits on ChatGPT Free or Go?
For some accounts, yes. OpenAI says credit purchases are currently available to a limited group of Free and Go users.
Should I turn on automatic reload for ChatGPT credits?
Automatic reload is convenient, but it can create recurring spend. Set it only if you understand the threshold, target balance and monthly limit.
Why these pages exist
OpenAI's products change quickly, and the difference between an included allowance, purchased credits, banked resets and referral rewards is easy to miss. Each answer links back to the official OpenAI source used. Where I give a personal estimate—such as how long 500 credits might last—I label it as an estimate rather than an OpenAI promise.