Use Copilot in Excel to check outside counsel invoices against budget

What This Does

Copilot in Excel builds PivotTables, formulas and conditional formatting from a plain-language request. Here you point it at a sheet of invoice lines and ask which matters and phases ran over the budget you agreed with the firm. You get a one-page view to take into the budget conversation, and the PDF invoice stays your source of truth.

Before You Start

• Copilot in Excel needs a Microsoft 365 Copilot license, and not every company has bought one. Microsoft's own page says Copilot may be missing from your subscription or switched off by your organization's settings. Look for the Copilot icon in the lower-right corner of Excel. If it is not there, ask your IT team which license you hold, or read Microsoft's Copilot in Excel support page for how to check.
• You have the invoice data typed or pasted into one sheet, one row per invoice line, with these columns: Matter Code, Firm, Phase, Hours, Fees and Phase Budget.
• The Matter Code is your internal code. Do not paste the time-entry narratives. Narratives can describe privileged strategy, so leave that column out of the sheet entirely.
• Use the workbook only inside your company's licensed Microsoft 365 account, and check with IT whether invoice data counts as confidential under your outside counsel agreement.

Steps

1. Build the sheet

Make one row per invoice line. Use a code for the firm (Firm A) if the workbook will be shared. Put the agreed budget for that matter phase in the Phase Budget column on every row of that phase. Format the data as a table so Copilot can see where it starts and ends.

2. Open Copilot and choose plan mode

Select the Copilot icon in the lower-right corner of Excel. Microsoft's page says Copilot in Excel opens in edit mode by default, which means it changes your workbook directly. It also offers plan mode, where Copilot writes out a plan for you to review and confirm before it edits anything, and chat mode, which answers questions without changing the workbook. Pick plan mode for this task. Check the mode selector in the Copilot pane, and if you cannot find it, say "Show me your plan before you change anything" in your prompt.

3. Ask for the PivotTable and the flags

Type a prompt such as:

"Create a PivotTable on a new sheet that sums Fees and Hours by Matter Code and Phase, next to the sum of Phase Budget. Then add a column that shows Fees minus Phase Budget for each phase. Apply conditional formatting that shades any phase where Fees are above the budget."

Read the plan Copilot shows. Confirm it only touches the new sheet and does not alter your source rows. Then approve it. Microsoft's page says you can watch the changes happen in the workbook and use the Stop button in the lower-right corner of the chat box to pause.

4. Check the result by hand

Pick two phases from the PivotTable, one flagged over budget and one not. Open the PDF invoice and add up the fee lines for each phase yourself. Compare your totals with the PivotTable. If either differs, look for rows Copilot or your paste dropped, a phase spelled two ways, or a budget entered on only some rows. Fix the sheet and ask Copilot to rebuild the PivotTable.

5. Take the flags to the billing conversation

Copilot shows you where the numbers exceed the budget. It does not know whether the work was approved as out of scope or covered by a billing guideline exception. Read your engagement terms and the firm's budget updates before you question a line.

Real Example

Scenario: The quarterly invoice from Firm A on a vendor dispute covers two phases. Your agreed budgets (invented example) are 9,500 for Document Review and 5,000 for Research.

What you do: The sheet holds five invoice lines. Document Review has three lines with fees of 4,200, 3,150 and 2,800. Research has two lines with fees of 1,800 and 2,200. You ask Copilot for the PivotTable and over-budget shading.

What you get: Document Review totals 10,150 against 9,500, so it is over by 650 and shaded. Research totals 4,000 against 5,000, so it is under by 1,000 and left unshaded. You add the Document Review lines on the PDF yourself (4,200 plus 3,150 plus 2,800), confirm 10,150, and then write to the firm asking what drove the extra 650.

Tips

• Keep a "Budget Source" note on the sheet saying which budget letter or email the numbers came from, so the check can be repeated next quarter.
• Ask Copilot in chat mode when you only want a question answered, such as "Which phase has the most hours?" Chat mode does not change the workbook.
• Save a copy of the sheet before you approve any edit that touches the source rows.

Tool interfaces change. If a button has moved, look for the Copilot icon or a similar AI option in the same area of the ribbon or the lower-right corner of the window.