Supplier Price Creep Checker

Which supplier prices quietly went up, and what does it cost you?

Paste the lines from your supplier invoices: date, item, quantity, unit price. The page lines up every purchase of each item, flags the ones that crept up, finds the invoices that were a one-off overcharge, checks any contract price you give it, and totals what the move costs you over a year. It writes a credit-request email for each supplier.

Your invoices are read in this browser tab and never leave your device. It compares prices you give it; it cannot tell whether a price rise was justified or whether you are owed a credit.

1. Your invoice lines

A CSV or a pasted spreadsheet range with a header row. Required columns: date, item, qty, and unit price (or total plus qty). Optional: supplier, unit (case, lb), SKU, contract price. Export line items from your accounting software or type them in; two or more purchases of an item are needed to see a change.

Choose a CSV file …or paste the lines

2. What counts as a problem

Flag creep at or above (percent)

Flag a one-off above neighbours by (percent)

Your business name for the emails (optional)

Choose a file or paste the lines, then click Check the invoices.

How it decides, and what it leaves out

Creep: an item whose latest price is at or above your threshold over its first price, bought at least twice. The annual cost is that gap times the quantity bought per year at the pace in your data, shown only with 28 or more days between first and last invoice.
One-off: a single purchase priced above both its neighbours by your threshold, where the neighbours agree within half of it. Likely an error or surcharge worth a credit request; it is left out of the annual figure.
Contract: any line priced above the contract price you gave, by quantity.
Price index: for each supplier, what a typical order of the compared items costs at the latest prices against the first prices.
Not decided: whether a rise was justified by a notice or contract term, pack-size or unit changes (items are matched by supplier and item name or SKU; different unit labels are flagged), tax and delivery fees, rebates, or whether a credit is owed. Prices are as you typed them.

Common questions

How do I know if my supplier is raising prices?

Compare what you paid for the same item on each invoice. Paste your invoice lines (date, item, quantity, unit price) and this page lines up every purchase of each item, shows the first price, the latest price and the percentage move, and sorts items by what the move costs you over a year.

What is the difference between price creep and a one-off overcharge?

Creep is a price that steps up and stays up. A one-off is a single invoice priced well above the invoices on either side of it, which is more often a keying error or a surcharge that should be credited. The page separates the two and drafts a credit request for the second kind.

How is the annual cost worked out?

The gap between the latest and the first price, times the quantity you bought per year at the pace in your data. It needs at least 28 days between the first and last invoice; with less, it shows no annual figure rather than a guess.

Can it check against my contract or quoted price?

Yes. Add a contract price column and every line priced above it is listed as an overcharge with the dollar difference, and a credit request email is drafted for each supplier.

Are my invoices uploaded anywhere?

No. They are read in your browser and nothing is sent; a test in the code asserts there are no network calls.