Do I need a Microsoft 365 Copilot licence to use Copilot in Excel?

Not for the basics. Microsoft lists a Copilot Chat eligible Microsoft 365 business or enterprise subscription as enough for standard access to Copilot in Excel. A paid Microsoft 365 Copilot licence adds priority access and the model picker. Your organisation's settings still decide what you see, so check with your Microsoft 365 admin if Copilot does not appear.

What happened to the COPILOT function in Excel?

Microsoft withdrew it. From 14 September 2026 the COPILOT worksheet function is no longer available. Existing cached results remain visible, but a cell returns a #NAME? error as soon as it recalculates. Microsoft points users to the Copilot pane for similar tasks, so replace any COPILOT formulas in live models before they break a month-end refresh.

Is Python in Excel safe to use with confidential finance data?

Microsoft states that Python in Excel code runs in hypervisor-isolated containers within your organisation's compliance boundary in the Microsoft Cloud, with no network access and no access to your device, account or user token, and that data is not persisted in the cloud. Follow your own data classification rules too, and review the Python code before you trust a result.

Why can I not choose Claude models in Copilot in Excel?

In the UK, EU and EFTA, Microsoft ships Anthropic's models switched off by default, because they are currently outside the EU Data Boundary and in-country processing commitments. An AI Administrator or Global Administrator can opt in through the Microsoft 365 admin center. The model picker also needs a commercial Microsoft 365 Copilot or Microsoft 365 Premium subscription.

Can Copilot in Excel replace review by a qualified accountant?

No. Microsoft's own FAQ warns that Copilot can make mistakes and advises against using it for decisions in sensitive areas such as finance. Treat it as a fast assistant for structure, formulas and first drafts, then apply the same review, reconciliation and sign-off you would use for any spreadsheet that feeds reporting or tax returns.

Copilot in Excel for Finance Teams: What It Does Well

Copilot in Excel now edits workbooks for you. It builds formulas, tables, PivotTables and charts, works across sheets and, in Edit with Copilot, can run Python for deeper analysis. For finance teams it is strongest at first drafts: variance schedules, matching helpers, data clean-up and commentary. Microsoft itself advises against relying on it for finance decisions, so every output needs a human check.

At a glance

Three modes: edit (Copilot changes the workbook), plan (it proposes steps first) and chat only (no changes).
Full features in Excel for Windows, Mac and the web. iPad, iPhone and Android have fewer modes for now.
Python can now be used inside Edit with Copilot for statistics, simulations and charts.
The COPILOT worksheet function was withdrawn on 14 September 2026. Cells that use it return #NAME? when they recalculate.
Review tools: Show Changes now marks Copilot's edits, and chat replies link to the cells they changed.
UK tenants: Anthropic's Claude models are off by default until an admin turns them on.

What Copilot in Excel can do in October 2026

Microsoft's Get started page lists what Copilot can now do directly in a workbook: add, rename and delete worksheets; write formulas and apply calculations across sheets; create and edit charts, PivotTables and shapes; sort, filter, and apply conditional formatting and data validation; summarise data and surface trends and outliers; fetch web information with citations; and pull data from other workbooks in OneDrive, SharePoint or on your computer. It uses Excel's own features, so what it builds stays editable.

The big change this year is Edit with Copilot, previously called Agent Mode, which appeared in Microsoft's Copilot release notes in March 2026. You describe a multi-step task, such as "build an expense tracker with variance formulas", and Copilot carries it out. In August 2026 Microsoft added Python to this mode, so Copilot can run Python in Excel for advanced analysis and write the results into the sheet. In September 2026 two review features followed: links in the chat reply that jump to each change, and Copilot attribution in the Show Changes pane.

Three modes control how much freedom Copilot has:

Mode	What happens	Use it for
Edit (default)	Copilot changes the workbook directly	Building new sheets on a copy
Plan	Copilot proposes a plan you confirm first	Anything touching a live model
Chat only	Answers in the pane, no changes	Questions about a file you must not alter

Who gets it. Copilot in Excel is part of Microsoft Copilot Chat. Users with a Copilot Chat eligible Microsoft 365 business or enterprise subscription get standard access, and a paid Microsoft 365 Copilot licence adds priority access and the model picker. Admins cannot switch off Copilot in Excel separately from Copilot Chat.

A UK detail on models. Microsoft turns Anthropic's models on by default for most commercial customers, but not in the UK, the EU or EFTA, because Anthropic models are currently excluded from the EU Data Boundary and in-country processing commitments. Your admin decides whether to enable them, so the model choices you see in Excel depend on that tenant setting.

Where it helps a finance team most

Task	How Copilot helps	What you still check
Budget vs actual	Builds the variance sheet and formulas	Signs, totals, code mapping
Bank or ledger matching	Adds match flags and exception lists	Each unmatched item
Data clean-up	Splits columns, fixes text dates and codes	Row counts before and after
Aged debt	Buckets invoices by days outstanding	The as-at date used
Month-end commentary	Drafts variance explanations	Every number quoted
Deeper analysis	Python statistics and charts	The code and its assumptions

The common thread: Copilot is fast at structure and first drafts. It does not know your chart of accounts, your cut-off rules or why a number moved.

Where to check its work

Microsoft is direct in its FAQ: Copilot "can sometimes make mistakes, misinterpret information, or produce inaccurate results", and it tells users to "Avoid using Copilot for decisions in sensitive areas such as finance". That does not make it useless for finance teams. It makes review compulsory. A practical checklist:

Reconcile totals first to a source you trust, such as the trial balance, the bank statement or the ledger export.
Read every formula Copilot writes. Ask it to explain a formula in plain English, then confirm the ranges reach the last row, references are absolute where they should be, and no numbers are typed into the formula.
Check signs and periods. Credits stored as negatives, a financial year starting in April, the right as-at date.
Use Show Changes. It now shows which edits came from Copilot, and the chat reply links to each change.
Experiment on a copy, or with AutoSave off. Microsoft's tips page suggests turning AutoSave off to try Copilot changes without saving them. Once saved, changes are visible to everyone with access to the file, including co-authors. Undo and version history are your safety net.
Review Python output. Microsoft states that Python in Excel code runs in isolated containers in the Microsoft Cloud, has no network access and cannot reach your device or account, and that data is not persisted there. Still read the code, because a wrong filter produces a confident, wrong chart.

A note for VAT workbooks under Making Tax Digital

This is general information, not tax advice. HMRC's VAT Notice 700/22 treats linked spreadsheet cells, such as a formula that mirrors a value from another sheet, as a digital link, but it does not treat cut and paste or copy and paste as one. If a workbook sits in your Making Tax Digital for VAT chain, tell Copilot to use formulas that reference the source data rather than pasting values, then check that it did.

Prepare your data so Copilot gets it right

Most weak Copilot results trace back to how the data is laid out, not to the prompt. Before you ask:

Format the data as an Excel table with one header row and clear column names such as InvoiceDate, CostCentre and NetAmountGBP.
Remove merged cells, blank rows and subtotal rows from inside the data. Totals belong below the table or on another sheet.
Make dates real dates. Exports from systems set up for the US often arrive as text or in month-first order. Convert them before analysis.
Store codes as text, so cost centre 0450 keeps its leading zero.
Save as .xlsx. Microsoft notes that Strict Open XML Spreadsheet files are not supported, and Copilot editing needs Calculation Options set to Automatic.
Name tables and columns in your prompts. Microsoft's own advice is to be specific, name the columns or ranges, start broad and then refine.

Practice prompts for finance teams

Try these on a copy of a real workbook, swapping in your own table names.

"Use plan mode. I want a budget vs actual sheet from tblActuals and tblBudget by CostCentre and Month, with variance and variance percentage. Show me the plan before changing anything."
"Add a column to tblInvoices that places each unpaid invoice into 0 to 30, 31 to 60, 61 to 90 or over 90 days, based on DueDate and the as-at date in cell B1. Use a formula, not values."
"Explain step by step what the formula in F12 does and list every cell it depends on."
"Flag rows in tblBank with no matching Reference and Amount in tblLedger. Put the exceptions on a new sheet with a count at the top."
"Create a PivotTable on a new sheet showing NetAmountGBP by CostCentre for April 2026 to March 2027."
"Check this workbook for numbers typed directly into formulas and list where they are."
"Using Python, chart the monthly spread of expense claims by department and list any claim far outside its department's usual range. Show me the code you ran."
"Draft three sentences of month-end commentary on the three largest variances in the Variance sheet. Quote only figures that appear in the sheet."

Prompts 1 and 2 matter most: asking for a plan and asking for formulas rather than values keep the workbook auditable.

Rolling it out without losing control

Clear out old COPILOT formulas. Search existing models for the function and replace those cells, because they break on recalculation.
Agree a review rule. Any schedule that Copilot builds or changes and that feeds reporting gets a second-person check, just like a manually built one.
Keep source extracts read-only and let Copilot work on copies.
Write down prompts that work for recurring jobs, so month end is repeatable. Microsoft's tips page also describes workbook rules and custom skills for repeatable tasks.
Train the team together, so everyone applies the same checks.

When the analysis outgrows a workbook, read our guide to Excel or Power BI.

How CertTulen Academy can help

CertTulen Academy, a Microsoft Training Services Partner, runs live online Copilot training led by Microsoft Certified Trainers. For finance staff starting out, the half-day AI-3025 Work Smarter with AI course is a practical starting point, and AB-730 Transform Business Workflows with Generative AI goes further, from Copilot Chat and prompting to analysing data in Excel and other Microsoft 365 apps, and prepares for the AB-730 AI Business Professional exam. Finance teams can book a private cohort, or contact us for a batch that suits your time zone.