Single Line Bar Codes are printed on the receipt. For the receipts or the test codes, a standard 13 digit EAN-13 is used for validation.
EAN-13 is referred to "The European Article Numbering System (EAN)" which is a superset of U.P.C. EAN-13 consists of 13 numbers.
If further assistance is required, submit a ticket to Punchh Support. (For help submitting a ticket, click here)