Microsoft 365 changes in October 2026: redesigned Copilot, new costs and usage-based billing — what to check in the tenant of your Mexico operation

On September 28, 2026 Microsoft unveiled the new Copilot as an “OS for work”, with three tabs: Home, Code and Autopilot. Rollout is gradual and, as Maya Comunicación reported, it comes with new costs.

Around the same time, r/sysadmin circulated a list of 30+ Microsoft 365 changes landing in October, and r/msp warned that Microsoft will switch on usage-based billing automatically through CSP partners. If your Mexico operation gets Microsoft 365 through a local reseller, or through HQ, this concerns you.

What changes for the people in your Mexico office

For the accountant in Monterrey, the visible change is that Copilot stops being a button inside Word and becomes an app with three tabs. Home is the assistant they already use. Code writes and reviews code. Autopilot is the new one: you give it a goal and it chains the steps by itself.

Not everyone gets it the same day. Rollout is gradual, so in one office some people will have Autopilot and others will not. Tell the local team before they open a ticket asking why their colleague has it and they do not.

The October list mixes small tweaks with changes people do notice in Teams, Outlook and the admin center. In our experience the big change is rarely the problem. The button that moved and nobody announced is.

Which Copilot features are billed separately

Your per-user license is still a fixed monthly fee. The new features, especially the ones that run tasks and agents, are billed on top, and part of that by consumption: you pay for what gets used, not a flat amount.

Microsoft did not publish a simple “included, not included” table. The practical rule: before switching anything new on in Copilot, ask your reseller in writing whether it sits inside the license or generates consumption.

ProcessBi

Item	Per-user license	Usage-based billing (UBB)
What you pay	The same every month	Whatever the features consume
Who decides	You, when assigning licenses	Any user who touches the feature
Where it shows up	On your usual invoice	As an extra charge via the CSP
Risk	Paying for seats nobody uses	A charge nobody approved

How to avoid charges nobody approved

What r/msp is flagging is that usage-based billing turns on without the partner doing anything. The charge lands on the reseller and the reseller passes it on. For a foreign company this gets messy fast: the Mexican reseller invoices in pesos, HQ sees it weeks later, and nobody remembers who enabled what. Three things to do this week:

1. Ask the reseller in writing to keep pay-as-you-go disabled on your tenant, or capped at a monthly amount you approve. Keep the email.
2. Review who is global admin on the tenant, which is your company account in Microsoft 365. If the contractor who left in 2024 is still there, remove them today. An admin can switch on features that bill.
3. Set a budget and alerts on any consumption subscription tied to the tenant, and send the alert to whoever pays, not only to IT.

Policies before Autopilot acts on its own

Autopilot will be able to do things: read mail, move files, send messages. Useful, and also the fastest way for someone in sales to “tidy up” a shared folder by accident.

Before enabling it, decide who can create agents, which data they reach and which actions need a human to approve. My take: start with a pilot of three or four people and read-only permissions. If you have not reviewed which apps already hold access to the tenant, do that first with the guide on auditing OAuth apps in Microsoft 365.

Let’s talk

And in your Mexico operation?

If your Mexico site pays Microsoft 365 through a reseller and nobody has looked at the tenant in months, October is the month to do it.

At ProcessBi the tenant and licensing review is part of the support plan: who is admin, what is switched on, what bills separately and how to cap consumption. We also manage the CSP relationship locally so the invoice carries no surprises, in MXN or USD.

Book your free assessment — we reply the same business day.