Use AI with spreadsheets carefully

Content checked against the listed guidance on November 5, 2026.

Use fictional or anonymized sample rows.

Ask for the formula’s assumptions and explanation.

Test on a copy before relying on the result.

Describe the layout with sample data

Explain the columns, the result you want and which spreadsheet app you use. A tiny fictional example can show the structure without exposing real customer, employee or financial records.

Do not paste confidential sheets or upload them unless your organization allows it and you understand the service’s data handling.

Ask for a formula and an explanation

Ask the assistant to state the assumed cell ranges, describe the formula in plain language and identify edge cases such as blanks or duplicate values.

If a formula is unfamiliar, ask for a simpler version or a small worked example. Do not copy a formula into the live file just because it appears plausible.

Make a copy of the spreadsheet or use a blank test sheet.
Try typical, blank, unexpected and boundary values.
Compare the output with a result you can calculate independently.
Check ranges and references before using the formula elsewhere.

Keep a human check in the loop

A spreadsheet can produce a wrong answer without showing an obvious error. Verify important totals with a second method and ask a qualified colleague to review formulas that affect payments, reporting or decisions.

Keep a note of what the formula is meant to do so the next person can maintain it.

Try this prompt

I use [EXCEL OR GOOGLE SHEETS]. Columns: [COLUMN NAMES]. Using this fictional sample, suggest a formula to [TASK]. Explain each part, state assumptions, and show how to test blanks and unusual values. Do not assume access to my actual spreadsheet.

Sample:
[SMALL MADE-UP EXAMPLE]

Concrete example

Sample input

Fictional sheet: A2:A4 contains 12, 8 and 10. Request: total these three sample values.

Illustrative output

A possible Excel or Sheets formula is =SUM(A2:A4), which adds the values in that range. For this example, check that the result is 30; test separately with a blank and a text value.

Limitations to keep in mind

A plausible-looking formula can calculate the wrong thing, especially with blanks, text, dates or changing ranges. Test it on a copy with known answers; get qualified review for important financial or reporting decisions.