HI there,
I am doing some research and have no prior experience with Square. I was wondering if it is possible to read a small data (like an id) from an iphone (or android) during nfc payment at a square terminal ?
Thanks Tom.
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No, it’s not possible to read any data from an iPhone or Android device during an NFC payment at a Square Terminal using Square’s APIs or SDKs. The NFC payment process is designed to securely transmit payment information only. It doesn’t provide a mechanism for reading additional data from the device.
This answer was reviewed by @Bryan-Square.
Ok thanks - how about a subsequent tap (ie after the payment has been successful) on the payment machine/screen? Could some contact data be read at that point by an add on ?
What contact data are you looking to read? Once the payment is completed you can get the payment object from our APIs. 
actually I just want to get a unique id from the phone that will identify a customer uniquely. This is not a repeat customer of any customer that the square system knows about. I was hoping I could use an app or a card in the phone wallet to do this ?
Currently, there isn’t a unique ID that you can use to identify a customer across all Square sellers nor is there a database that you would be able to reference customers in this manner.
Thanks Bryan,
well I was hoping to get an id from the phone by tapping so I can get the payers id (a uuid or something which I will do something with). The same way I can tap my phone at the grocery store and it gets some customer detail so it knows to credit my loyalty account. Is that not possible ?
That currently isn’t possible today with tap payments with Square. We’re constantly working to improve our features based on feedback like this, so I’ll be sure to share your request to the API product team.
Thanks, so just to confirm, there would be no way to
- From the add on software, ask the payer if they would like to take part in something, and
- If they elect to do so, wait for the iphone to tap the screen
- transfer some data in the nfc payload to the pos terminal ?
- Have the addon take some action
Thanks Tom
That’s correct, this isn’t currently possible with Square’s developer tools.
I just like this forum, every time I find helpful insights..