Payment ID numbers are processor-specific and function much like a merchant ID number on an invoice. In contrast, these IDs are assigned by the processor that facilitates the purchase and are assigned randomly. Order numbers are private to the business making the sale and wouldn’t necessarily be included in a processor’s invoice. Transaction IDs shouldn’t be confused with terminal IDs, purchase orders, or payment ID numbers. Computers use them to sort relevant information tied to a transaction. Transaction IDs are often easily located on a receipt or invoice near other essential transaction data like the merchant name, billing address, date of purchase, and order number. The number is used to identify a transaction for recordkeeping purposes. A transaction ID is a sequence of numbers generated during the electronic transfer of funds from a consumer to a merchant.
