Last week we reported that someone had dug up clues from the webpage source code suggesting ChatGPT and Codex quotas might be merged, and just a few days later, OpenAI officially confirmed it in its Help Center. Starting in December, ChatGPT and Codex under the Plus, Pro, and Business plans will share the same usage quota. However, it’s important to know first that although the two will share a quota going forward, not every time you open ChatGPT to chat will it consume the quota available to Codex.

OpenAI confirms ChatGPT and Codex will share a quota starting in December! But Instant chats won’t count against the quota.
OpenAI added 〈 to the Help CenterUnderstand the usage limits for ChatGPT and Codex.This article mentions that starting in December, the usage quotas for the Plus, Pro, and Business plans will be shared between ChatGPT and Codex. The official reason given is that because Work’s agent features will be integrated into the core ChatGPT experience, quota calculation will therefore be combined with Codex.

In addition, according to foreign media BleepingComputer According to the report, OpenAI also sent an email notifying subscribers, mentioning that in the coming weeks it will first find a small group of users to test the merged Chat and Work interface, while Codex will remain independent in the ChatGPT desktop app:

So after the merger, how will the shared quota be calculated? Officially, it states that in the future, ChatGPT and Codex usage will be calculated using Tokens.
As for how much will be deducted, it depends on the model you choose and the task you assign. The more advanced the model and the more complex the task, the more it usually consumes. For example, using ChatGPT for analysis that requires deep reasoning, or having Codex rewrite the code for an entire project, will consume more than simple Q&A.
No specific quota figures for each plan have been announced yet, nor has a conversion method for each type of task been provided, so it is still impossible to determine how many Tokens each plan can use after the merger. However, for people who are heavy users of both ChatGPT and Codex, under the same plan, the number of uses will definitely decrease.
However, not all ChatGPT conversations deduct from your quota. In the email OpenAI sent to users, it mentioned: “Instant mode is the exception.” Using Instant for real-time chat does not consume the shared quota. In other words, if you use Instant for quick conversations such as looking up information or asking a simple question, you won’t use up Codex quota.
Once the change officially takes effect in December, users can go to “Settings → Usage” to view their remaining shared quota and reset time. When they reach the limit, there are three options: wait for the quota to reset, upgrade their plan, or purchase credits to continue using it; the credits option only applies to eligible features:

OpenAI also said it is carefully preparing for this transition and expects most users will not have to wait for quota resets more frequently than they do now. Additionally, the Work and Codex quotas for the Pro plan were doubled on October 29.
Source: KOCPC Chinese