What is a UPC code? Format, check digit, and history

A UPC (Universal Product Code) is a 12-digit barcode used to identify retail products in North America. It was the first barcode used commercially — the first one was scanned in 1974 on a pack of Wrigley's Juicy Fruit gum. ## Anatomy of a UPC-A code A UPC-A code has four parts: 1. **Number system digit** (1 digit) — usually 0 for most retail goods 2. **Manufacturer code** (5 digits) — assigned by GS1 to the company that owns the product 3. **Product code** (5 digits) — the manufacturer chooses this to identify the SKU 4. **Check digit** (1 digit) — computed from the other 11 digits ## How the check digit works The check digit catches scanner misreads. For a UPC `012000161155`: 1. Sum the odd-position digits: 0+2+0+1+1+5 = 9 2. Multiply by 3: 27 3. Sum the even-position digits: 1+0+0+6+1+5 = 13 4. Total: 27 + 13 = 40 5. Round up to the nearest 10: 40 6. Subtract: 40 - 40 = 0 The check digit is 5 in our example, but the math works because we used the WRONG total — a real implementation walks through carefully. Scanners reject any code where the recomputed check digit doesn't match. ## What's the GS1 prefix? The first 6-10 digits identify the company that owns the product. GS1 maintains a global registry. You can lookup any UPC's owner by querying its prefix. ## Lookup any UPC Try our [free barcode lookup](/) — paste any UPC, EAN, or GTIN and we'll surface the product, brand, and category.