A fiscal receipt from an online register usually carries a QR code. The customer can scan it with a smartphone to check that the receipt is registered in the tax system and that its details are correct.
For a shop this means receipt quality matters: the QR code must print sharply and the paper roll must be good quality. A code on a faded or torn receipt is hard to read. Receipt printer heads wear over time, so regular checks and cleaning help.
Get current information on how and with which apps receipts can be checked from the tax authorities' official sources. BDB helps choose reliable receipt printers and their consumables.