HourSaved

Explain a bill or invoice line by line in plain words

Paste a vendor's bill and what you agreed to, and the AI explains each line, re-adds the math and lists charges worth questioning, so you can spot errors before you pay.

Setup
5 min
Saves
About 15 min a use (our estimate)
Level
Easy
Last checked
Works with
Any AI chat

Run once on made-up data on with Claude. One run, not proof.

Version 1 · Draft: not yet approved by the owner · How we test

What this does

Paste a bill and notes on what you agreed to. The AI explains each line, re-adds the math, flags charges that don't match, and drafts polite questions for the vendor. You check the agreement and decide whether to pay, ask or push back.

This is not financial, tax or legal advice. Questions about sales tax go to your accountant.

Before you start

  • Any AI chat (ChatGPT, Claude, Gemini or Copilot).
  • The bill as text, plus the quote, contract terms or your notes.
  • Setup: about 5 minutes (our estimate).
  • Privacy: remove account numbers, your address and any card details first.

Steps

  1. Copy the bill's text and remove account numbers and payment details.
  2. Write the key terms you agreed to in a few lines.
  3. Paste the prompt into a new AI chat with both.
  4. Check each flag against the agreement and your calendar.
  5. Edit the questions you want to ask into your own words.
  6. Contact the vendor yourself before you pay. The FTC advises small businesses to set clear steps for approving invoices and check them closely, since some scammers send fake ones.

The prompt

Prompt · fill the [brackets]
Explain this bill to me line by line in plain words. Use only the bill and the notes I give you. Don't contact the vendor or send anything.

For each line: what it is, how it was worked out, and whether it matches what we agreed.
Then:
- Re-add the math. Show any line or total that doesn't add up.
- List anything I should question: charges not in our agreement, counts that look off, dates that don't fit, vague fees.
- Write a short, polite list of questions I could ask the vendor.
If a line is too vague to explain, write UNCLEAR. Don't guess what a fee is for. Don't say whether tax is right; flag it for my accountant.

What we agreed:
[paste your quote, contract terms or notes]

The bill:
[paste the bill, with account numbers removed]

Before and after: the made-up input, then the real output the AI gave us.

Try it with made-up data

Maple & Rye Cafe (made up) got this from Bluewater Commercial Cleaning (made up).

What we agreed: Weekly deep clean every Monday, $165 per visit. Floor strip and wax every 3 months, $220; last done in April 2030. No surcharges in the agreement. We never asked for an after-hours visit.

Invoice #B-3381 · Date 2030-07-01 · Terms Net 15 · Service period June 2030

  1. Weekly deep clean, 5 visits × $165.00 ... $825.00
  2. Floor strip & wax ... $220.00
  3. Supplies surcharge (8%) ... $83.60
  4. After-hours fee, 06/14 ... $45.00
  5. Fuel surcharge ... $12.00

Subtotal ... $1,185.60 · Sales tax (7%) ... $82.99 · Total due ... $1,268.59

What the AI gave us

Line by line

  1. Weekly deep clean: 5 × $165 = $825.00. The rate matches. But June 2030 has only 4 Mondays (June 3, 10, 17, 24), so 5 visits doesn't fit a Mondays-only schedule.
  2. Floor strip and wax: $220 matches the price. The last wax was in April, so every 3 months points to July, not June.
  3. Supplies surcharge: 8% of lines 1 and 2 ($1,045.00) = $83.60. The math is right, but your agreement lists no surcharges.
  4. After-hours fee, June 14: June 14, 2030 is a Friday, not a cleaning Monday, and you didn't ask for an after-hours visit. UNCLEAR what this covers.
  5. Fuel surcharge, $12.00: not in your agreement. UNCLEAR how it was worked out.

Math check: The subtotal of $1,185.60 adds up. 7% of $1,185.60 = $82.99. The total of $1,268.59 adds up. Whether these services should be taxed is a question for your accountant.

If only agreed charges stood: 4 visits × $165 = $660.00, plus the wax if you accept the early date.

Questions for Bluewater

  • Which dates were the 5 deep cleans? We count 4 Mondays in June.
  • Was the floor wax due in June? Our last one was in April.
  • Where do the supplies and fuel surcharges come from? They aren't in our agreement.
  • What happened on Friday, June 14, and who asked for it?

Good: it caught the extra visit, the early wax and both surcharges, and its math was right. A person still had to dig out the signed agreement to confirm "no surcharges" and decide what to pay while waiting for answers.

Check before you send

  • Each flag holds up against your actual agreement.
  • Dates and visit counts match your calendar or sign-in sheet.
  • The math matches when you re-add it.
  • Tax questions go to your accountant.
  • Your questions to the vendor are polite and specific.

Don't paste

  • Your bank, card or account numbers, or the vendor's payment details.
  • Logins to vendor portals.
  • Employee names or private details on the bill.

When not to use this

  • No record of what you agreed. Find the quote or contract first.
  • Legal disputes or large contracts. Talk to your lawyer or accountant.
  • Bills you suspect are fake. Look up the vendor's real contact details yourself.

Questions owners ask

How do I check if an invoice is correct?

Compare each line's price, quantity and dates to what you agreed. Re-add the math and ask about any fee that wasn't agreed.

Can AI read a photo of my bill?

Some can, but they may misread numbers. Typed text is safer to check.

Sources

Related guides

Money adminCompare two vendor quotes side by sideMoney adminTurn your messy money notes into a tidy question list for your bookkeeper or CPAMoney adminSort a month of bank transactions into expense categories (you check, your accountant decides)

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The newsletter

One new guide a week, free.

Start with the free starter: three short emails over your first week. First the 15-minute Start here guide, then the three jobs we'd hand to AI first, then one question about what eats your week. The first two come with a practice task and the check you do before anything goes out. After that, one new guide every Tuesday: one task, the prompt to paste and the check to do. At most one ad, always labeled.

  1. Day 1Your first 15 minutes with a free AI assistant
  2. Day 3Summarize a long email thread into decisions, open questions and next steps
    Draft routine email replies in your own voice, without promises you didn't approve
    Write payment reminder emails in three tones (friendly, firm, final)
  3. Day 6What eats your week? Reply in one line, plus how the weekly guide works