Categorize 419 ledger transactions into an Excel template with ChatGPT agent

Posted

Sep 5, 2025 by Jason Staats (@jasononfirms)

·

Last checked

Oct 16, 2026

·

Method:

How we verify

Evidence: Screenshots or logsThe source shows screenshots, a transcript or the agent's output.

Outcome

Given an Excel ledger template and 419 transactions, ChatGPT agent asked for help on ambiguous merchants, then keyed in all ~400 rows and took 4 minutes.

Agent

ChatGPT agent

The source didn't share its exact prompt, so we wrote this from what it describes.

Here's a task I'd like your help with. Read it all the way through before you start.

Goal: Fill in my Excel ledger template by putting each transaction under the right expense category.

Check with me first: Do I have rules for how certain merchants should be categorized?

What I'll give you:
- My Excel ledger template
- My transactions (for example a CSV)

Rules:
- Categorize the transactions the way a person would, and do the obvious ones (like Uber as Travel) yourself.
- Give me a short list of only the merchants you truly can't place, and wait for my answer.
- Work in my template. Don't change its structure.
- If something is missing or unclear, ask me instead of guessing.

Output: The completed spreadsheet with every transaction filled in, plus a note of any you weren't sure about.

You'll know it worked when: every transaction sits in a category I'd agree with.

Works best when: I use a business account that keeps my data private.

Here's a task I'd like your help with. Read it all the way through before you start.

Goal: Categorize every transaction into my Excel ledger template the way a bookkeeper would.

Quick check first: tell me if anything below is missing or unclear.

Inputs (fill in or confirm):
- The ledger template
- Transactions CSV
- Merchant rules I already use
- Categories allowed
- Fiscal year and any split transactions

Rules:
- Use only the template's categories; never invent new ones.
- Apply my merchant rules first, then judge the rest from merchant and memo.
- Add a confidence column and a note for anything uncertain.
- Keep totals unchanged: check the sum before and after.
- Treat refunds as negative amounts in the original category.
- Don't change dates or amounts.
- Summarize totals per category at the end.

If you get stuck: If a transaction could fit two categories, pick one, mark it low confidence and list it for me. If a login, CAPTCHA or two-step code appears, stop and ask me to handle it; never guess or store passwords.

Verify before you finish: Check row count and total amount match the CSV.

Output: The filled template plus a list of low-confidence items.

Done when: every transaction is categorized and totals reconcile.

Source

https://x.com/jasononfirms/status/1963993526515192040