OpenAI's FAQ says the original remains usable until retirement but becomes read-only, so finish essential edits first.
Source: OpenAI's Custom GPT retirement and migration FAQ. OpenAI says dates may change, so check the FAQ for your plan.
Keep reading
Custom GPT to Plugin Migration ChecklistA step-by-step checklist to move a Custom GPT without losing behavior.What Commonly Breaks When You Migrate a Custom GPTActions, tone, sharing settings and file handling are the usual trouble spots.When are Custom GPTs being retired?OpenAI lists December 11, 2026 as the planned retirement date, subject to change.