Where can I find specifications for Receipt Barcodes?

Question

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 1

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.