Enterprise

OpenAI's Custom GPT shutdown puts small-business AI workflows on a 73-day clock

Creation of new GPTs has closed for Enterprise workspaces, existing custom GPTs stop running December 11, and any GPT wired to a CRM or email tool through custom actions won't migrate automatically.

By Asher Glick· Enterprise software desk·2026-09-28·3 min read

Photo: Unsplash / Rolf van Root — Laptop screen showing the ChatGPT interface

OpenAI has put a 73-day clock on every Custom GPT running inside an Enterprise workspace. New GPT creation in affected workspaces closed on September 25, 2026; existing GPTs stop working on December 11. Admins were notified on September 11, and the migration experience was targeted to open on September 17, which OpenAI describes as “a target, not a guarantee that the option is available in every workspace.”

The retirement lands harder than the calendar suggests, because migration isn’t lift-and-shift. According to the FAQ, “GPT custom actions do not transfer through the migration workflow.” That single line is the story. Custom actions are the API hooks that let a GPT reach into a CRM, pull from Gmail, or push into an outreach tool. Any small-business team, 5 to 30 people, that wired a lead-qualifier or a follow-up drafter to its stack now has to rebuild those integrations by hand, most likely as a custom MCP server.

The rest of what doesn’t carry over reads like a checklist of everything an operator actually cares about. Sharing settings reset (migrated plugins start private). People who had access to the original GPT don’t automatically get access to the replacement. Conversation starters and previous chats may not copy. The GPT’s selected model doesn’t carry over. OpenAI warns that a migrated plugin may respond differently and recommends testing familiar prompts plus at least one harder case before sharing.

Personal accounts are already halfway through the same door. New GPT creation and publishing are gone on Free, Go, Plus, and Pro. Existing GPTs still run, but editing requires an eligible subscription, and any public GPT built inside an affected Enterprise workspace retires on December 11 regardless of which tier the end user is on.

This arrives one week after Nimble’s AI sequences launch last week and eleven days after OpenAI turned ChatGPT into a storefront with sponsored agents and a HubSpot integration. The pattern isn’t subtle. The hobbyist-facing surface is being cleared, and the commercial surface is being rebuilt around plugins, agents, and paid distribution. OpenAI has said the dates are subject to change. The teams that treated a Custom GPT as production infrastructure are finding out what that phrase actually meant.

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