By Paul Derrington, Jr.
CEO | Chief Engineer | Research Engineer | Editor, D-CSIL
3 min read
Key Takeaways
OpenAI says that starting in December, Plus, Pro, and Business plans will draw from one usage allowance shared across ChatGPT and Codex, measured in tokens instead of separate message limits. Instant chat is the one exception: it will not draw from the allowance. OpenAI has not published the size of each plan’s allowance or an exact start date, so subscribers cannot yet tell whether the shared pool is bigger or smaller than the two separate limits it replaces.
Today: two separate meters
Right now, ChatGPT and Codex are metered separately for most paid subscribers. ChatGPT Work and Codex already share one agentic allowance, but ordinary chats with the advanced models run on their own limits — so a long research session in chat costs nothing against your Codex time.
That split was part of the appeal for people who lean on both. A researcher posting as yurimo on Hacker News called having Pro-tier chat and Codex “decoupled in terms of billing” one big reason to stay on OpenAI’s Pro plan. Anthropic already counts Claude chats and Claude Code against the same limits, according to madrobot’s reporting — so OpenAI is now following its rival’s model.
December: one shared pool, counted in tokens
OpenAI’s help center article, “Understanding ChatGPT and Codex usage limits,” says: “Starting in December, Plus, Pro, and Business plans’ usage allowance will be shared across ChatGPT and Codex as we bring the agentic capabilities of Work into the main ChatGPT experience.” The page appeared on Saturday, October 31, and OpenAI has also emailed subscribers about the change.
Usage “will be measured in tokens, the units of information a model processes and generates,” OpenAI says. “How much of your allowance you use will depend on the model you choose and the task you ask it to do. More advanced models and complex tasks generally use more of your allowance.” From December, a heavy Codex run and a long chat with a reasoning model both come out of the same pool.
OpenAI says you will see your combined remaining usage and reset times in Settings, then Usage. If you reach the limit, you can wait for the reset, upgrade your plan, or buy credits to keep using eligible features.
What stays outside the meter — and what OpenAI hasn’t said
The one carve-out OpenAI names is Instant chat: “Instant chat will not draw from your usage.” Quick everyday questions on the fast default model stay free of the meter; everything heavier counts.
What the help page does not say matters as much as what it does. It gives no token allowance for any plan, so there is no way yet to compare the shared pool with the two separate limits it replaces. It names no exact December date, does not mention Free, Enterprise, or Edu plans, and does not say whether per-model message caps in chat stay alongside the new pool. OpenAI has published no blog post about the change beyond the help page.
The timing is notable: the change lands days after OpenAI cancelled a planned cut to Pro 200’s Work and Codex allowance — a cut that would have taken it from 20 times to 10 times the Plus allowance — and doubled Pro 100 and Pro 500 instead, according to madrobot’s reporting.
Verdict: check your usage before December
If you use ChatGPT lightly and Codex rarely, this probably changes nothing — OpenAI says it expects “most users won’t need to wait for their usage to reset more often than they do now.” But if you lean on both products at once, the two budgets you used to manage separately are now one, and a big coding afternoon can eat into your chat time.
The practical move is simple: open Settings, then Usage, once a week from now, and watch how much each side burns. Until OpenAI publishes the per-plan token figures, your own usage is the only number that tells you whether the shared pool is enough.