AI Invoice Double-Check

From Line Check AI. Leak: INVOICES. Setup time: about 30 minutes. After that: about 2 minutes per delivery plus 15 minutes a week.

What you'll get: every supplier invoice gets checked against what you ordered and what actually showed up, and price jumps get flagged before you pay.

Formats in this playbook:

1. Written step-by-step guide (with copy-paste prompts)
2. 60-90 second video script
3. AI chat coach system prompt

Tools and steps were checked October 19, 2026. These products change often, so if a button has moved, use the help links below for the current version.

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Part 1: The Written Guide

Why bother?

Short deliveries, wrong prices, substitutions and double charges are easy to miss when invoices pile up. Checking each one by hand takes time nobody has. A photo plus AI makes a first pass fast, and you only look closely at what gets flagged.

The tools (all real and available now)

Tool	What it does here	Cost	Link
ChatGPT (photo upload)	Reads a photo of an invoice, lists the line items, and compares them to your order and your last known prices. Image uploads work on the free plan (PNG, JPEG, non-animated GIF).	Free plan works	ChatGPT image inputs · File uploads
Claude (an alternative)	Same idea: upload the invoice photo inside a project with your price list.	Free plan works	Claude projects
Google Sheets	Your price log: item, supplier, unit, last price, date.	Free	Google Sheets
MarginEdge (upgrade path)	Restaurant back-office software that captures and codes invoices automatically, with price alerts and accounting sync.	Published pricing: $350 per location per month	MarginEdge invoice processing · Pricing
xtraCHEF by Toast (upgrade path, Toast users)	Toast's invoice processing and costing tool.	Quote-based	Toast invoice processing

Our recommendation for most owners: start free with phone photos, ChatGPT or Claude, and a Google Sheet price log. Consider MarginEdge or xtraCHEF once invoice volume or multiple locations make the monthly price worth it.

The golden rules

1. Check the delivery at the door. Count cases and weigh key items before the driver leaves, when you can still note shortages on the invoice.
2. AI is a first pass, not an accountant. It can misread handwriting or blurry photos. Confirm every flag against the paper invoice.
3. Don't upload more than you need. Crop out bank details, account numbers and signatures before you upload a photo.
4. Disputes go through your sales rep in writing, with the invoice number and a photo.
5. Keep the price log current. It's what makes the price check work.

Step 1: Build your price log (20 minutes)

List your top 20-30 items by spend from recent invoices: item, supplier, pack size/unit, price, date. Prompt #1 can pull these from a few invoice photos.

📋 Copy-paste prompt #1: Price log from recent invoices

Here are photos of my recent supplier invoices. Make a table I can paste into Google Sheets with columns: supplier, item, pack size/unit, unit price, invoice date, invoice number. Only list what you can clearly read. If a value is unclear, write "CHECK" instead of guessing.
[ATTACH PHOTOS]

Step 2: Set up your "Invoice Check" project (10 minutes)

Create a project in ChatGPT or Claude. Paste your price log into the project instructions or upload it as a file, along with Prompt #2's rules.

📋 Prompt #2: Project rules

You double-check supplier invoices for my restaurant.
For each invoice photo I upload (and my order list or delivery notes, if I give them):
1. List every line item: item, quantity, unit, unit price, line total.
2. Flag: (a) any unit price different from my price log, with the difference in $ and %; (b) quantities that don't match my order or delivery notes; (c) math errors (quantity × price ≠ line total, or lines ≠ invoice total); (d) items I didn't order; (e) possible duplicate invoices (same supplier, date and total as one I've shown you).
3. End with "OK TO PAY" or "CHECK BEFORE PAYING" and a short list of what to check.
Never guess unclear numbers; mark them "UNREADABLE".
My price log: """[PASTE]"""

Step 3: At every delivery (2 minutes)

1. Check counts and weights at the door. Write shortages on the invoice and get the driver's initials if your supplier allows it.
2. Take a clear, flat photo of each invoice page in good light.

Step 4: Weekly 15-minute check

1. Upload the week's invoice photos to the project with Prompt #3.
2. Confirm each flag on the paper invoice.
3. Send any disputes to your sales rep using Prompt #4.
4. Update the price log with confirmed new prices.

📋 Prompt #3: Weekly check

Check these invoices using the project rules. Here's what we ordered and any delivery notes: """[PASTE or "none"]"""
[ATTACH INVOICE PHOTOS]

📋 Prompt #4: Credit request to your sales rep

Write a short, polite email to my sales rep at [SUPPLIER] asking for a credit or correction. Invoice #[NUMBER], dated [DATE]. Issue: [e.g., "billed 4 cases of romaine, received 3" / "price on chicken thighs went from $X to $Y with no notice"]. Ask them to confirm the correction in writing. Sign it [NAME], [RESTAURANT].

📋 Prompt #5: Monthly price trend summary

Here's my price log for the last 3 months. Show the 10 items whose unit price rose the most (in $ and %), and suggest 2-3 questions I should ask my suppliers or alternatives I should price-check. Don't invent market prices.
"""[PASTE]"""

Your checklist

• Price log for top 20-30 items in Google Sheets
• "Invoice Check" project set up with Prompt #2
• Door check routine explained to whoever receives deliveries
• Weekly 15-minute invoice check on the calendar
• Ran Prompt #5 at the end of the month

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Part 2: Video Script (about 75 seconds)

Format: phone video, host at the back door or office desk, screen recordings cut in. Captions on.

Time	On screen	Voiceover / on camera
0:00–0:07	A stack of invoices on a desk	"When was the last time someone actually checked these? Let's make it a two-minute job."
0:07–0:20	Host checking cases at the back door	"At the door: count the cases, weigh the key stuff, and write shortages on the invoice before the driver leaves."
0:20–0:38	Screen: photo of an invoice uploaded to ChatGPT, a table with flags	"Snap a photo of the invoice. Upload it to ChatGPT or Claude with your price list. It lists every line and flags price jumps, short counts and math errors."
0:38–0:55	Host comparing a flag with the paper invoice	"Then you check each flag on the paper. AI can misread things, so it's a first pass, not your accountant."
0:55–1:05	Screen: short credit-request email	"Found a problem? Have it write a polite email to your rep with the invoice number."
1:05–1:15	End card: "Line Check AI: free 5-minute checkup" with the URL	"Want to find your other money leaks? Take our free five-minute checkup. Link's right here."

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Part 3: AI Chat Coach System Prompt

Members paste this into a ChatGPT or Claude Project as the project instructions.

You are "Invoice Coach," a friendly, practical helper from Line Check AI. You help busy restaurant owners catch short deliveries, wrong prices and billing errors on supplier invoices.

WHO YOU'RE TALKING TO
- Independent restaurant owners and managers. Busy, not accountants. Plain words, short steps.

YOUR JOBS
1. Help build a price log of their top 20-30 items (supplier, item, unit, price, date) from invoice photos. Mark anything unclear "CHECK".
2. Check invoices: list line items; flag price changes vs. the log (in $ and %), quantity mismatches vs. order/delivery notes, math errors, items not ordered, and possible duplicates. End with "OK TO PAY" or "CHECK BEFORE PAYING".
3. Teach the routine: check counts and weights at the door, photograph invoices flat in good light, a weekly 15-minute check, and a monthly price trend review.
4. Draft polite credit-request emails to sales reps with invoice number, date and the specific issue.
5. For high volume or multiple locations, mention paid tools such as MarginEdge (published pricing $350 per location per month) or xtraCHEF by Toast (quote-based) as options to evaluate.

HARD LIMITS
- Never guess unclear numbers; mark them "UNREADABLE" and ask for a clearer photo.
- Always tell the owner to confirm flags against the paper invoice before disputing or paying.
- Remind them to crop out bank details, account numbers and signatures before uploading.
- Don't give accounting, tax or legal advice; suggest their bookkeeper or accountant for those.
- Don't invent market prices or statistics.
- You can't pay, dispute or contact suppliers yourself; the owner does.

STYLE
- Calm, practical, short. End with the next step.

FIRST MESSAGE
"Hi! I'm your Invoice Coach. Upload a photo of a recent supplier invoice (crop out any bank or account numbers) and I'll walk through it with you."