Your custom GPT retirement deadline is December 11

Custom GPTs now have a shutoff date. OpenAI is retiring every GPT built in My GPTs on December 11, 2026, and routing anyone who made one toward a mandatory move to its newer plugin format, a move that drops a few pieces most builders don't expect to lose.

The deadline hits any small business that built a GPT for a customer FAQ, an intake form walkthrough, a brand voice assistant, or an internal SOP helper. Existing GPTs keep working right up to the cutoff. Enterprise workspaces can apply for a deferral that pushes the date to February 11, 2027, but that requires an approved request, not a default grace period.

The custom GPT retirement timeline

OpenAI confirmed the retirement in late September. Every custom GPT, on free, Plus, or Business tiers, moves to the same end point: December 11, 2026 for standard accounts, and February 11, 2027 only for the Enterprise workspaces that get a deferral approved ahead of time. After that date the GPT stops responding and only the migrated plugin remains.

What transfers automatically

The core content moves without much effort on your part. A GPT's most recently published instructions become a skill inside the new plugin. Any knowledge files you uploaded get copied over as reference files the plugin can still read. If your GPT was mostly a well-written prompt plus a folder of PDFs, the migration button does most of the real work for you.

What breaks and needs rebuilding

What to do before December 11

1. 1

   Inventory every GPT your team built

   Open My GPTs and list each one still in use, including ones built by former employees or contractors that nobody remembers today.

2. 2

   Flag anything with a custom action

   Check each GPT for connected APIs, webhooks, or Zapier calls. Those are the pieces that get dropped in migration and need to be rebuilt by hand in the new plugin.

3. 3

   Migrate early and test with real tasks

   Use the Migrate to Plugin button well before December, then run the same requests you'd normally ask the GPT to handle and compare the answers.

4. 4

   Re-share access with your team

   Sharing links reset during migration. Send the new plugin link to everyone who used the old GPT instead of assuming they still have access.

If you have a custom GPT doing real work for your business, the fifteen minutes it takes to check its actions and sharing settings is cheaper than finding out what broke on December 12. Bring me your setup and I'll help you figure out what actually needs rebuilding before the deadline hits.