September 29, 2026. OpenAI is retiring custom GPTs, and its migration FAQ, updated in the last few days, now gives December 11, 2026 as the scheduled retirement date, with February 11, 2027 only for Enterprise workspaces that hold an approved deferral. New GPT creation and publishing are already switched off on personal accounts, Free, Go, Plus and Pro, according to OpenAI's GPTs help page. The replacement is plugins, and the part that will cost small businesses and agencies the most is stated plainly: custom actions, the API calls a GPT makes to your CRM, booking system or database, do not transfer.
Key numbers
| Item | Number |
|---|---|
| Custom GPT retirement, standard date | December 11, 2026 |
| Retirement with an approved Enterprise deferral | February 11, 2027 |
| Announcement in the ChatGPT release notes | September 11, 2026 |
| Enterprise migration target (the GPTs help page still says September 17) | September 22, 2026 |
| Banner target, delayed-banner workspaces | October 1, 2026 |
| End of new custom GPTs, Enterprise (planned) (was September 25 in the FAQ on September 18) | October 26, 2026 |
| Personal plans without GPT creation | Free, Go, Plus and Pro |
| Custom actions carried into the plugin (rebuild through an app or a custom MCP server) | none |
OpenAI Help Center FAQ, GPTs page and release notes read on 29 September 2026; earlier dates as quoted by MIXED on 18 September 2026.
What OpenAI has announced so far
- The decision. The ChatGPT release notes for September 11 say OpenAI plans to retire custom GPTs across ChatGPT plans and offer a migration path to plugins, with timing that may vary by plan and workspace.
- The Enterprise timeline. An admin notice on September 11, a migration target of September 22, a banner target of October 1 for workspaces that opted into delayed banners, the end of new custom GPT creation planned for October 26, and retirement on December 11. OpenAI says the dates are subject to change.
- The dates have already moved once. On September 18 MIXED quoted the same FAQ giving September 17 for migration and September 25 for the end of new GPTs, and OpenAI's GPTs page still says September 17. Other plans "are expected to follow the same timeline", that page says, so follow the notice in your own account.
- Public GPTs go dark. At retirement, custom GPTs and their GPT pages become inaccessible, and public GPTs built in affected Enterprise workspaces follow the Enterprise timeline even when used from another plan.
What moves to a plugin, and what does not
- Moves: the instructions become a skill, knowledge files are copied as reference files, and connected apps are added as apps.
- Does not move: custom actions. Features that depend on them stop working in the plugin until you rebuild the connection, through an available app or a custom MCP server, and OpenAI warns a rebuilt integration may not match every capability of the original.
- Also left behind: the selected model, existing conversations and sharing settings. A migrated plugin starts private, and making it public needs a separate plugin submission.
- Housekeeping that bites: migration uses the latest published version, so drafts do not transfer, and once migrated the original GPT turns read-only and its creator cannot delete it.
What it means for operators
Treat this as an inventory job with a deadline. List every GPT your team relies on, who owns it and whether it calls a custom action, because those are rebuilds rather than migrations. Save a handful of real prompts and accepted outputs first; OpenAI itself recommends comparing familiar prompts and at least one harder case before relying on the plugin. Publish any draft you want to keep, since drafts cannot be migrated and Enterprise workspaces lose GPT creation on October 26 if the plan holds. If a public GPT was part of how prospects found you inside ChatGPT, its page disappears in December, so move that entry point to a page you own and to the answers AI assistants actually cite, which is the work behind our AI search optimization service. Rebuilding custom actions as a governed MCP server is ordinary integration work; if you want it done once and documented, you can hire an AI engineer through us, and if client data flows through those tools, read our note on client data in ChatGPT before you reconnect anything.
Frequently Asked Questions
OpenAI's migration FAQ gives December 11, 2026 as the scheduled retirement date, and February 11, 2027 for Enterprise workspaces with a qualified, approved deferral. OpenAI says the dates may change and that timing can vary by plan and workspace, so check the notice in the account where the GPT was created.
Not on a personal account. OpenAI's GPTs help page says new GPT creation and publishing are not available on Free, Go, Plus or Pro, although existing GPTs remain usable. In Business, Enterprise and Edu workspaces it depends on workspace settings, and for affected Enterprise workspaces the end of new custom GPT creation is planned for October 26, 2026.
They do not transfer. Instructions, knowledge files and connected apps migrate, but any feature that relied on a custom action stops working in the plugin until you rebuild the connection through an available app or a custom MCP server, and OpenAI says to test that integration before switching.
No. At the retirement date custom GPTs and their GPT pages become inaccessible, and migration does not carry over public sharing. A migrated plugin starts private, and making it public requires a separate plugin submission.