The question I hear after Issue 1 is "OK, but how do I actually use these?" So this issue is hands-on, for one very common job: cleaning and summarising a monthly sales or job-cost spreadsheet.
Tools change quickly. This reflects what each product offered in October 2026. The title is a rule of thumb, not a law: Claude and Copilot also work inside Excel, as the first bullets say.
The rule of thumb
- Working inside one spreadsheet? Use an AI tool built into Excel. ChatGPT has an Excel add-in that opens in a sidebar and can build, explain and update workbooks. Copilot in Excel does similar work if you have the right Microsoft licence, and Claude has an Excel add-in on paid plans.
- Have a file but no add-in? Upload it to ChatGPT or Claude chat. Both accept Excel and CSV files and can analyse them.
- Same job on many files, every month? That is where Claude Code can earn its place. It works on your computer, in a folder you choose, and can read files, write scripts and run them. Claude Code's own documentation says it isn't limited to programming. It has permission modes, so you can have it ask before every edit or only propose a plan first. Pick one of those when you start, rather than leaving it on a more automatic setting.
An illustrative example (not a client)
A 30-person contracting firm exports a job-cost sheet each month. Someone spends a good part of a day fixing names, dates and duplicates, then building a summary by job and by month. The steps below are the same ones that person would follow.
Step 1: Prepare and protect. Save a copy of the file. Delete anything you don't need, such as personal phone numbers. Check your plan's data terms before you upload any customer or financial data. Business plans from the major vendors typically offer stronger commitments than free or personal accounts, but read the terms for yours.
Step 2: Clean. Upload the copy, or open the add-in, and paste:
This spreadsheet has one row per cost entry. Columns: Job, Date, Vendor, Category, Amount.
1. List every problem you can see: inconsistent job names, dates in different formats, blank cells, possible duplicate rows, amounts stored as text.
2. Do NOT change anything yet. Show me the list with row numbers.
Read the list. Then: "Fix the issues you listed. Put the result on a new sheet called Clean and leave the original sheet untouched. Tell me every change you made."
Step 3: Summarise. Paste:
On the Clean sheet, build a summary table: total Amount by Job and by Month (months as columns), with a grand total row and column. Use formulas, not typed numbers, so I can see how each cell is calculated. Add a short note listing any assumptions.
Step 4: Check your work. Never skip this. AI can be confidently wrong, especially on spreadsheets.
- Ask: "Show me the formula behind three cells and explain each in plain language."
- Spot-check yourself. Pick two jobs and add them up with a simple SUM on the original. Compare to the AI's number.
- Confirm the grand total equals the original total, and the number of rows matches, apart from rows you agreed to remove.
- Keep the original untouched so you can go back.
Step 5: Only if you repeat it monthly, consider Claude Code. Put twelve exported files in a folder. In Claude Code, start in plan mode (it proposes before it edits) or manual-approval mode and ask for a script that cleans and summarises every file the same way. Run it on a copy of the folder, review what it did, and compare a few totals by hand. If you're not comfortable reading what it proposes, ask someone who is, or stay with the chat approach.
When not to reach for Claude Code
- A one-off question, an email or one document. Plain chat is simpler.
- Anything touching live systems, payments or sensitive records you don't have approval to share.
- Any job where nobody will check the result.
Three ground rules
- Copy first, original untouched.
- You verify the numbers. Spot-check totals every time.
- Check the plan's data terms before sensitive data goes in.
Not sure which process to try first?
The free Process Scan takes a couple of minutes, needs no email, and suggests a first process to look at and tools to test. If you’d like a written plan afterwards, the paid Process Scan is $350 CAD.
The full cheat sheet has copyable prompts for 15 common tasks. Reply and tell me what you’d like covered next.
Sean Martin
Adapting Services