How to check a UPC list against Amazon in bulk

Your supplier sends a price list with thousands of UPCs, and Seller Central lets you look them up one at a time. Here is how to check a UPC list against Amazon in bulk, and the mistakes that make a bulk UPC scan match the wrong products.

1. Get the barcodes into one clean column

Put every UPC (12 digits) or EAN (13 digits) in one column, with the supplier's price in another. Format the barcode column as text before you paste anything into it. Remove spaces and dashes; some suppliers write 0-12345-67890-5.

2. Repair what the spreadsheet broke

Excel treats barcodes as numbers, which breaks them in two ways:

• Lost leading zeros: 012345678905 becomes 12345678905, 11 digits that match nothing. Pad a short UPC back to 12 digits with zeros at the front, and a short EAN back to 13.
• Scientific notation: a long code shows as 1.23457E+11. Change the column to text or to a number format with no decimals to get the full code back.

3. Throw out the invalid codes

The last digit of every UPC and EAN is a check digit calculated from the others. A code that fails the check has a typo, and looking it up wastes time or, worse, finds a different product. Test doubtful codes with our free UPC and EAN validator. A UPC is also a valid EAN with a zero in front, which matters when your list mixes the two.

4. Look up the codes in batches

Amazon's catalog can be searched by UPC or EAN, but only a handful of codes per request, and with rate limits. That is why checking a long list by hand or one code at a time takes hours. A bulk tool sends the codes in batches and collects the matches for you.

5. Check the matches before you trust them

• Not found: the product is not sold on Amazon in this marketplace, or the code is wrong. Keep these in a separate list; they are not opportunities yet.
• Several ASINs for one code: the same barcode is often used on a single unit and on bundles. Check each listing.
• Multipacks: when the listing is a 3-pack and your supplier sells singles, you need three units per sale. Divide the listing's price, or multiply your cost, before you judge the profit.

More on these traps in UPC, EAN and ASIN matching mistakes.

6. Then check what the matches are worth

A match is only the start. For every matched ASIN you still need the Buy Box price, the fees, the sales and the competition before you know whether to buy it. Our guide to analyzing a supplier price list covers those steps.

Do it in one upload

Wholesale Analyzer does the whole bulk UPC scan for you. Upload the supplier's Excel or CSV file (up to 200,000 rows) and choose UPC, EAN, ASIN or ISBN. It removes spaces and dashes, undoes scientific notation and restores lost leading zeros. It then matches each code to Amazon, including a UPC that Amazon lists as an EAN. Products that could not be found are marked so you can check them, multipacks are detected with the cost per unit, and every matched product gets its profit, ROI and a BUY, REVIEW or AVOID decision. You can try it on 50 products of your own list for free every month.