Automations
AI Agents Are Moving to Pay-Per-Task. Cost One Before You Switch It On
Microsoft now bills its agents by usage. The five numbers that tell you whether one pays
The usage bill is the number everyone watches. The review time is the number that decides it.
On 25 September Microsoft changed how it charges for AI at work. The Microsoft 365 Copilot licence, still US$30 per user per month, keeps covering chat and Copilot inside the Office apps. Everything agent-shaped, Cowork, Code, Autopilot and the newest frontier models, is now billed by usage in Copilot Credits. Satya Nadella had already told investors the business model was moving from "per-seat" to "per-seat-plus-consumption".
That turns an AI subscription into something closer to a phone bill: a fixed plan plus a meter. For a small business it changes the question from "is the licence worth it?" to "is this particular task worth running?". That one you can answer on the back of an envelope.
What does an agent task really cost?
Five numbers. Two of them are the ones on the invoice. The other three are the ones that usually decide the answer.
Costing an agent task · Five numbers
Runs per month. How many times the task happens. Count them from last month, do not estimate.
Price per run. The usage cost of one run. Microsoft says it depends on the model, how much of your information the agent reads, how many tools it calls and how long it runs. Measure it on ten real runs.
Review time. Minutes a person spends checking each result, multiplied by what an hour of their time costs.
Redos. The share of runs that come out wrong and get done again, by the agent or by hand.
Time saved. Minutes the task used to take a person, multiplied by the same hourly cost. This is the value side.
Where most costings go wrong: they count the usage and forget the review. Checking the agent's work is real work, done by the same people whose time you were trying to save.
A worked example
An illustration, not a quote: a practice drafting payment reminders. These numbers are made up to show the arithmetic. Put your own in.
| Line | Working | Monthly |
|---|---|---|
| Usage | 200 drafts x 40c | $80 |
| Review | 200 x 1 minute at $60 an hour | $200 |
| Redos | 5% of drafts, 5 minutes each | $50 |
| True cost | $330 | |
| Time saved | 200 x 5 minutes at $60 an hour | $1,000 |
It pays, comfortably. But look at which line is biggest. Review costs two and a half times the usage. Halve the review time, by making the drafts consistent enough to skim, and the task improves more than it would from any price cut.
Now change one assumption. If each reminder only took a person one minute to write in the first place, time saved drops to $200 and the agent loses money. Same tool, same price, different task. That is why the costing is per task, not per product.
Before you switch usage billing on
- Set a spending limit first. Microsoft's usage features are off by default, and admins can cap spend by company, group or user. From 2 November, new Copilot Business licences through resellers come with a preset default limit. Decide your own number deliberately.
- Measure ten runs. Price per run and review minutes, on your real work, before any rollout.
- Re-cost quarterly. Prices move quickly. The same week, Alibaba announced voice AI price cuts reported at up to 95 percent. Keep "price per run" as one number you update.
Sources: Microsoft on the new Copilot, Microsoft Learn, usage-based billing and Copilot Credits, The Decoder on Alibaba's price cuts.
Key takeaways
- Seat plus meterThe licence is now the floor, not the whole price. Agent work is metered on top, like cloud spend.
- Review time dominatesIn most small-business tasks the minutes a person spends checking the output cost more than the usage itself.
- Cap it firstUsage features can be limited per company, group or person. Set the limit before the first run.
Frequently asked
Does every Copilot prompt now cost extra?
No. Microsoft says the Microsoft 365 Copilot licence still covers Copilot Chat and Copilot inside Word, Excel, PowerPoint, Outlook and Teams. The metered part is the agent work: Cowork, Code, Autopilot and the frontier models.
What does a Copilot Credit cost?
Microsoft lists pay-as-you-go Copilot Credits at US$0.01 each, with a discount for buying a pool in advance. How many credits a task uses depends on the model, how much of your organisation's information it pulls in, how many tools it calls and how long it runs, so the only reliable number is one measured on your own task.
Can a usage bill run away from us?
It can if nobody sets a limit. Microsoft's usage features are off by default and administrators can set spending limits for the whole company, a group or a person. From 2 November 2026, new Copilot Business licences bought through a reseller come with usage billing switched on and a preset default spending limit.
Is this only a Microsoft thing?
No. Most agent products now charge per task, per minute or per token, and prices move quickly: this same week Alibaba announced voice AI price cuts reported at up to 95 percent. Build your costing so the price per run is one number you can update.