Where can I find specifications for Receipt Barcodes?
I have a question about the barcodes at the bottom of receipts. I am looking at writing some software around it and would be interested in any specs or 3rd party software packages surrounding it. What I really need is a solid source of information on these systems.
My understanding is that most point of sales systems support printing a barcode at the bottom of the receipt. What information does that bar code contain? I assume the information on the receipt such as the item purchased, the item cost, date etc?
Is there a single specification that all follow or does it vary from point of sale system to point of sale system?
Answer
The barcodes printed at the bottom of receipts are not defined by any standard. They exist only for internal use by the stores.
The barcoded data usually exists to identify a particular transaction, enabling a future lookup of the transaction to perform a return, or to perform a shipping function, or to serve as a kind of message digest validating that a receipt was generated by the retailer. Sometimes the barcodes serve as an entry code for a customer survey or for a prize drawing. Some barcodes may simply contain the URL of the retailer.
Each POS system generates their own unique barcodes. The code could contain a randomly generated UUID, or it could have a combination of date and transaction number. The symbology it is printed in could be Code 128, Code 39, PDF-417, a QR Code, or even a proprietary symbology.
The barcodes are not fixed - if a retailer upgrades their systems, they might produce different codes tomorrow.
Finally, if you are thinking of creating a "receipt storing app" for an iPhone, know that most retailers require the original paper receipt for returns, and will not accept a copy. Part of the cashier's task may be to validate the paper is genuine receipt tape pre-printed with the store's logo. It may be their process requires them to use a marker to strike-out the items that were returned. Receipts are controlled by the retailers because copies of receipts are used by shoplifters to return stolen merchandise.