Many merchants give their clients loyalty cards with barcodes. You can now use such cards to identify your customers by scanning barcodes from their loyalty cards. 

The Loyverse POS app, starting from version 2.18 for Android and version 2.32 for iOS, supports scanning customer codes. This function appears when adding a customer to the ticket. The cashier can add the customer to the receipt by scanning the barcode from his/her loyalty card with a barcode scanner or device camera. 

However, before doing that, the barcode from the customer's loyalty card (“customer code”) should be entered into the customer's profile. This is easy to do in the Back Office. You can also use the exporting-importing functionality to update your customer's list with code in bulk.

The cashier can also connect the customer code with customers when registering customers in the loyalty program and fill in the customer profile at the POS.  

For more details, check the help article: How to Add the Customer to the Receipt by Scanning a Barcode.