Why isn't my POS app recognizing customer card barcodes?

[ocastx]

We are trying to create physical (or digital) customer cards so that customers can be quickly identified at the POS. So far we tested the integrated barcode scanner in the Shopify POS iOS app to check which formats are detected. It seems like the scanner is able to detect common Code 128 barcodes for products. 

However, when creating a Code 128 barcode for a customer (using either their Shopify customer ID or their e-mail address) the app always shows "Barcode not recognized". 

Is there a specific format that needs to be incorporated into the barcode for the POS app to be able to recognize it? 

[Astasu]

Hello guys,

is there any answer. We are also planning to give out customer cards we need a way to quickly identify a customer at POS without typing every customer into the system.