Sort and rename messy invoices for taxes with Claude Code

Posted

Oct 14, 2025 by Martin Merschroth (via Lenny's Newsletter)

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Last checked

Oct 16, 2026

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Method:

How we verify

Evidence: Article or interviewA newsletter, journalist or interview account of what happened.

Outcome

Claude Code reads each file in a messy invoice folder, renames it to 'YYYY-MM-DD Vendor - Invoice - ProductOrService.pdf' and files it in the right folder.

Agent

Claude Code

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: Sort my messy invoice folder: rename each file clearly and move it into the right folder.

Check with me first: Which folder holds the invoices, and how do I want them grouped?

What I'll give you:
- The folder of invoices
- My folder structure (for example by year or vendor)

Rules:
- Read each file and rename it as 'YYYY-MM-DD Vendor - Invoice - ProductOrService.pdf'.
- Move each invoice into the right folder.
- If something is missing or unclear, ask me instead of guessing.
- Don't delete anything. Show me a few examples before doing the whole folder.

Output: A tidy, renamed folder plus a list of files you weren't sure about.

You'll know it worked when: every invoice has a clear name and sits in the right folder for tax time.

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

Goal: Sort and rename my invoice files for taxes.

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

Inputs (fill in or confirm):
- Invoice folder
- Folder structure
- Naming format
- Tax year and whether I need personal vs business split

Rules:
- Read each invoice for date, vendor, amount.
- Rename each file in the naming format I give you, e.g. 'YYYY-MM-DD Vendor - Invoice - ProductOrService.pdf'.
- Move into the structure.
- Log changes.
- Use the invoice date, not the file's modified date.
- Keep the original file extension and never edit file contents.
- Flag duplicates (same vendor, date and amount) instead of deleting them.
- Write a CSV summary per year: vendor, date, amount, currency, new file path.

Checkpoint: Show the plan before moving.

If you get stuck: If unreadable, put in 'check'. 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: Count files before and after. Check the CSV totals against a few invoices by hand.

Output: Rename log.

Done when: every invoice is renamed and filed.

Source

https://www.lennysnewsletter.com/p/everyone-should-be-using-claude-code