Apple Cash: Insufficient funds after purchase accepted?

Depends on who is attempting to bill your Apple Cash. If it is a primary payment method for purchases/subscriptions in the App Store with no other valid payment method, then your Apple Account will be disabled and you will be unable to use the App Store for downloads/updates until that payment has been made. If you gave your Apple Cash account number to a merchant for a purchase, then they likely have their own course of action,

Typically, if there are insufficient funds on an Apple Cash account, the transaction is declined at the POS. An exception can happen when paying at a restaurant and the tip is charged after the initial payment is approved. If the combined total exceeds the available account balance, it results in a negative balance on the Apple Cash account.

Even I was looking for same issues ,

I have been trying to make some purchases for my websites related to Glass bead Abrasives

If you find any solutions or any contact to apple pay support , post here

Thanks

[Edited by Moderator]