Custom GPTs, Plugins and Skills for Marketing Teams (2026)

#01What exactly is changing?

OpenAI's GPT help article opens with the plan: retire custom GPTs and help creators move workflows to plugins. The retirement FAQ gives the dates and mechanics.

Your existing conversations with GPTs stay accessible after retirement, according to the FAQ.

#02What are plugins and skills?

A skill is a reusable workflow: instructions, examples and sometimes code that ChatGPT can apply when a task matches. A plugin packages one or more skills with apps (connections to services such as Google Drive or Slack) and sometimes app templates. Some plugins hold only skills.

You find both under Plugins in the sidebar. Skills sit on the Skills tab of the Plugin Directory, where you can create one with chat, write one in the editor or upload one. Each eligible account includes a skill-creator skill that helps write new skills.

Our view: for marketing teams, skills are a better unit than GPTs were. A GPT was a separate chat you had to remember to open. An installed skill can be picked up automatically when the request matches, inside your normal chat or a Work task.

#03How do you migrate a team GPT?

The FAQ lays out the process. In practice:

1. Find which GPTs the team actually uses and who created each. Only the creator (or, in Enterprise, an admin) can migrate.
2. Finish essential edits and publish them. Migration uses the latest published version, and drafts don't transfer. Publishing doesn't mean sharing publicly.
3. Save three to five familiar prompts and one hard case for comparison.
4. In My GPTs, select Migrate to plugin.
5. Review the new skill and reference files, then run your saved prompts.
6. Rebuild any custom action through an available app, or a custom MCP server if needed. These don't transfer.
7. Share the plugin. In a managed workspace, Share Plugin can prefill the GPT's original audience. Confirm people can use it before asking them to switch.

#04Which marketing skills are worth building first?

Build skills for work your team repeats weekly and where consistency matters.

A skill draft you can paste into Create with chat:

Create a skill called "Ledgerline claim checker".
Purpose: review any marketing draft for claims.
Steps: 1) list every factual or comparative claim;
2) match each to the approved list in the reference file;
3) mark unmatched claims [NEEDS SOURCE] and banned ones
[REMOVE]; 4) return the draft with changes tracked as
before/after pairs. Never add new claims.
Reference file: approved-claims.md (attached).

#05Worked example: Ledgerline's GPT migration

Ledgerline is a fictional accounts-payable tool. Details are illustrative.

Ledgerline had four GPTs. An audit showed only two were used weekly: "Blog brief" and "LinkedIn rewriter". The other two were deleted from the plan rather than migrated.

"Blog brief" migrated cleanly: its instructions became a skill and its persona files became reference files. "LinkedIn rewriter" used a custom action that posted drafts into a scheduling tool; that did not transfer. The team replaced it with the scheduling tool's app where available and kept a manual paste step until it was tested. Both plugins were shared with the marketing group a week before the original GPTs went read-only.

#06What should you check before the next lesson?

• List the GPTs your team uses and note the creator of each.
• Check whether Skills appear under Plugins in your account.
• Migrate and test one GPT before December.
• Claude users: compare with Claude projects and brand voice and the Claude prompt library, which covers Claude Skills.

Next: Marketing strategy and positioning with ChatGPT. Or return to the ChatGPT for Marketers track.

#07Common questions

Can I still create a custom GPT? Not on personal plans. OpenAI says new GPT creation and publishing are not available on Free, Go, Plus or Pro. Some managed workspaces may still allow it, but OpenAI plans to retire custom GPTs and move them to plugins.

When do custom GPTs retire? OpenAI schedules standard retirement for 11 December 2026, with a later date of 11 February 2027 for FedRAMP workspaces and some Enterprise workspaces with an approved deferral. Follow the notice in your account.

What happens to a GPT when I migrate it? Its instructions become a skill in a new private plugin, knowledge files become reference files and connected apps are added as apps. Custom actions and the selected model do not carry over.