GPT-5.3-Codex Now Base Model for Copilot Business & Enterprise
GPT-5.3-Codex replaces GPT-4.1 as the default model for Copilot Business and Enterprise. It's the first long-term support model, guaranteed available through February 2027. GPT-4.1 deprecates June 1.
TL;DR
- GPT-5.3-Codex is now the default model for Copilot Business and Enterprise orgs, replacing GPT-4.1
- First long-term support (LTS) model guaranteed available through February 4, 2027
- GPT-4.1 deprecates June 1, 2026 when usage-based billing launches
New
- GPT-5.3-Codex as base model — All Copilot Business and Enterprise organizations now default to GPT-5.3-Codex unless your org has approved other models through internal review
- Long-term support guarantee — GPT-5.3-Codex is the first LTS model, available for 12 months from launch (February 5, 2026 through February 4, 2027), giving enterprises time for security and safety reviews
- Premium request multiplier — GPT-5.3-Codex carries a 1x multiplier; GPT-4.1 remains at 0x until deprecation
Breaking Changes
- GPT-4.1 deprecation — GPT-4.1 will be force-disabled on June 1, 2026 when usage-based billing launches. Contact your account team if you need more time to migrate
- Scope limited to Business/Enterprise — Copilot Pro, Pro+, and Free plans follow standard model timelines and are not affected by this change
Update: No action required if you're on Copilot Business or Enterprise — the switch is automatic. If you need to stay on GPT-4.1 temporarily, reach out to your GitHub account team before June 1, 2026.
Source: GitHub Changelog
