Customer left the store before the payment confirmation and her card was declined

[Tanzin]

My customer had left the store before the confirmation and her card was declined. Is there any chance to get in touch with her and ask for the payment again?

[JJ_]

Hello, @Tanzin. Welcome to the Square Community

The only way to contact your customer would be if you know their name and have a profile created for them on your Square account. Otherwise, we do not collect any contact information during the transaction.

I hope that you're able to solve this soon, and my advice is to make sure the transaction process is completed (including the receipt option screen to make sure the transaction is settled) before letting the customer go.