GPT-5.3-Codex becomes the Copilot base model for Business and Enterprise

GPT-5.3-Codex replaced GPT-4.1 as the base model for all Copilot Business and Enterprise organizations, at a 1x premium request multiplier. It is a long-term support model available through February 4, 2027.

Who is affected:

Copilot Business and Enterprise organizations that have not approved other models.

What to do:

Review premium request usage, since the base model now has a 1x multiplier.