What should we do when customers leave a open tab/credit card behind?

[theRusticLab]

The title of this thread has been edited from the original: OPEN TABS/CREDIT CARD LEFT BEHIND: WHEN SIGNATURES ARE REQUIRED/ENABLED

Was wondering what other people do when customers leave a open tab/credit card behind. We have a sign that states that any tabs/cards left behind will have a gratuity of 20% added to the total. 

However, my question is: what do you do when a signature is required to process a credit card transaction? Research has led me to believe that if the customer is physically not present, I can write 'card left behind' in the signature box.

Does anyone else do this? Is this recommended/legal? I want to make sure this is the best option for this type of situation.

[Helen]

Hello @theRusticLab! 
 

Hopefully another seller who runs a bar will reply here to let you know how they handle these cards But in the meantime, I shared your post with our a Disputes specialist here at Square to help prevent you from getting a dispute for one of these payments. The specialist recommend that you ask customer to sign something (a form/a receipt) to agree to your policy for cards left behind. Displaying a sign is good, but if you do receive a chargeback for one of these payments, having something signed is better. The Disputes specialist also wanted to remind you to always dip chip cards to the chip card reader. 

I hope this helps! If you have any other questions about this reply here to let me know.