Microsoft published notice MC1454373 to the Microsoft 365 Message Center on 14 August 2026. From 14 September the =COPILOT() worksheet function stops working in Excel, and Microsoft has updated its roadmap to say it will not take the feature forward. The Message Center is the administrative feed that carries changes of this kind to each organisation’s subscription.
The exposed population is small. The function ran as a preview through the Insider and Frontier programmes and required a Microsoft 365 Premium subscription, so few people hold it in a live workbook. Anyone still calling it in a working file has a fortnight to move that work.
Microsoft points users to the Copilot side pane, which covers the same categories of work by a different route. A formula spills results, recalculates when its inputs change and stays visible as part of the workbook’s logic. A side-pane answer is reviewed and applied by hand, so a monthly process built on the function needs rebuilding, and not simply repointing.
The date is the useful part. Copilot has changed every month this year, and a fixed date is rare enough to be worth using as a review point. Two questions are worth asking while the notice is open: who reads your Message Center, and who decides which Copilot capabilities are switched on.
For Penta clients, the Message Center is monitored as part of your managed service and the =COPILOT() withdrawal is already logged against affected subscriptions. Nothing is needed from you.
If you are not a Penta client and cannot say who reads your Message Center, that is the gap we fill.