What's changed, and what it means for your bill

A correction first

On 6 September we reported that this offer would end on 30 September. That date came from a third-party source, and it was wrong. Microsoft's own terms on its UK pricing page say the offer is available between 1 July and 31 December 2026. We've corrected it here and everywhere else on this site. The calculator wasn't affected - it has always used the £16.10 list price.

What the offer actually is

It applies to the Microsoft 365 Copilot Business add-on only - the per-person licence you add to a Microsoft 365 Business plan you already have. It isn't available on the bundles (Business Standard with Copilot at £18.10, Business Premium with Copilot at £24.60), on trials, or combined with other offers. It needs an annual commitment, and the promotional price applies to the first year only. The subscription then auto-renews at the standard rate.

Nothing changes on the usage side. Cowork is still billed at $0.01 per Copilot Credit on pay-as-you-go, and the pre-purchase discount tiers are unchanged. This is a licence price only.

What it means in pounds

For a 15-person firm buying before 31 December, the saving is £2.30 per person per month, which is £34.50 a month or £414 across the first year. For 30 people, double that. Worth having - but in year two the licence line goes back to £16.10, and that's the figure to budget for.

That's why this calculator and every cost guide on the site use £16.10. A budget built on £13.80 looks right for twelve months and then quietly breaks. If you're buying during the offer, take the saving and plan for the list price anyway.

What to check

If you're already licensing Copilot on the offer, note your renewal date - that's when the price changes. If you're still deciding, the offer is a reason to decide before 31 December, not a reason to license more people. The bigger question is still which desks earn a licence, and that answer is the same at £13.80 or £16.10.

Pre-purchase tiers, in the open

Until now, committed-credit pricing was something you asked a reseller about. The September guide sets it out: a one-year Pre-Purchase Plan with a discount that starts at 5% for 300,000 credits and rises in steps to 20% at 300 million. Unused credits expire at the end of the term.

For smaller businesses that puts the realistic saving at 5% to 6% - worth having once usage is predictable, not worth committing to before you know what a normal month looks like. We've corrected our own earlier note, which had suggested a flat committed rate of around $0.008; the published tiers replace it.

The rename

As of August 2026, the product formerly called Microsoft 365 Copilot is Microsoft Copilot. Cowork sits inside it, as before. Pricing, licensing and the Copilot Credit are unchanged - but expect both names on invoices, admin screens and documentation for a while. We're using both on this site until the old name fades.

Nothing else moved

Pay-as-you-go stays at $0.01 per credit, billed in US dollars. The guide's own estimation method - users, times a light/medium/heavy prompt mix, times price - is the one this calculator uses, so our figures still line up with Microsoft's.

What changed

During Microsoft's Frontier preview programme, Cowork usage wasn't billed. That grace period ended on 1 July 2026. From that date, every tenant needs usage-based billing configured in the Microsoft 365 admin centre - a payment method and a spending policy. Tenants that didn't set it up lost Cowork access entirely; it isn't a case of quietly accruing charges, the feature simply stops.

What it costs now

Pay-as-you-go usage is billed in Copilot Credits at Microsoft's list price of $0.01 per credit, in US dollars - so the pound cost moves with the exchange rate. Microsoft also offers a pre-purchase plan at a tiered discount for businesses that buy a year's volume upfront; if your usage is predictable, that's worth pricing against pay-as-you-go before you renew. (Updated September 2026: the tiers are now published - see the story above.)

What to check in your tenant

Three things, five minutes: that billing is configured (or deliberately not, if you've decided against Cowork); that spending limits and alerts are set at tenant and user level rather than left open; and who can actually use it - Cowork is off by default, and the sensible rollout is a named pilot group, not everyone.