Manufacturers label their products with barcodes to allow for rapid identification of the item using a scanner. Retailers use the manufacturers’ barcodes in conjunction with their own point-of-sale system to aid in check-out, monitor inventory and set prices. The most common barcode for retail sales in the U.S. is the Uniform Product Code (UPC), which is registered with the Uniform Code Council. Although UPCs usually contain 10 digits, some products require a truncated UPC (a UPC-E) due to size restrictions. Manufacturers can truncate UPCs by removing extra zeroes that are automatically re-inserted upon scanning.

Identify the final digit of the truncated UPC. Converting a full-length UPC (UPC-A) to UPC-E requires suppressing excess zeroes and identifying the operation performed with the final digit.

Place the final digit after the first two digits of the UPC-E if the final digit is a zero, one or two. Add four zeroes following that final digit. For example, if the truncated UPC is ABXYZ1 then the complete UPC-A is AB100-00XYZ

Locate the third digit if the truncated UPC ends with the number three. Insert five zeroes following the third digit and remove the final digit. For example, if the truncated UPC is AB5YZ3 then the complete UPC-A is AB500-000YZ

Insert five zeroes after the fourth digit of the truncated UPC if it ends with the number four. Remove the final digit. For example, if the truncated UPC is ABCDZ4 then the complete UPC-A is ABCD0-0000Z.

Fill in the suppressed zeroes if the truncated UPC ends with numbers five through nine. Insert four zeroes before the final digit of the UPC-E to expand it. For example, if the truncated UPC is ABCDE8 then the complete UPC-A is ABCDE-00008.