Custom GPTs Shut Off December 11: The 30-Minute Inventory Before You Hit Migrate

What happened. OpenAI is retiring custom GPTs across ChatGPT plans. The retirement date is December 11, 2026. Enterprise workspaces with an approved deferral get until February 11, 2027. The replacement is plugins, which bundle reusable instructions (called skills), reference files, and connected apps. For Enterprise workspaces, creating new custom GPTs is planned to end October 26.

What carries over. In My GPTs, select a GPT and choose Migrate to Plugin. The GPT's instructions become a skill, its knowledge files are copied into the plugin's reference files, and connected apps can come along. After migration, the original GPT stays usable but read-only until the retirement date.

What does not. Sharing settings, past conversations, Custom Actions, and the GPT's selected model do not transfer. That list is the whole job. Each gap is either a workflow that breaks or a security decision you get to make fresh.

Why it matters. If your team runs a quote writer, an intake assistant, or an SOP helper as a custom GPT, it stops working in December. The migrate button copies everything as-is, including knowledge files someone uploaded two years ago that may hold client names or pricing you would not share today.

The 30-minute inventory.

1. List every GPT. Open My GPTs on every account your team uses, including personal logins used for work. Write down the name, the owner, who uses it, and how often.
2. Drop the dead ones. Anything nobody has used in 60 days does not get migrated. Fewer copies of your files in fewer places.
3. Open the knowledge files first. Before you hit migrate, open each file. Remove or replace anything with client names, account numbers, or old pricing. The migration copies whatever is there.
4. Write down every Custom Action. Actions do not carry over. Note what each one connected to. If you are not rebuilding it, revoke the API key or login it used. The key keeps working after the GPT is gone.
5. Set sharing on purpose. Sharing does not transfer, so each plugin starts fresh. Share it with the people who need it. Skip public links for anything that touches internal work.
6. Retest on the new model. The selected model does not carry over. Run 3 real tasks through the migrated plugin and compare the output to what the GPT gave you.
7. Update your links. If a GPT link sits on your website, in an email signature, or in a training doc, plan for it to stop working and replace it.

Paste this into your business AI workspace, once per GPT:

Here are the instructions from a custom GPT my team uses: [paste instructions]. Here are the names of its knowledge files: [paste file names only]. Here is what its Custom Actions connected to: [list, or "none"]. 1) Rewrite the instructions as a clean, reusable skill. Keep every rule, and remove anything that names a specific client, person, password, or key. 2) List every line you removed and why. 3) From the file names, flag any file that likely holds client or financial data so I can check it before migrating. 4) Write 3 test tasks I should run on both the old GPT and the new plugin to confirm they behave the same. Do not guess about file contents you cannot see.

Keep it private. That prompt needs instructions and file names only. Never paste API keys, passwords, or client files into any AI tool.