Why is my transaction declined

[Chuckblevins]

Are prepaid debit cards usable on there and if so what goes for zip and CVV when no cvv is on card?

[PartyManiaMD]

Are you trying to use a prepaid debit card on a Square website? Typically they only work in person because they don't have a billing zip code. This is intentional because there is a LOT of fraud associated with prepaid debit cards and to protect the merchants you typically need a cvv and billing zipcode to verify that you're the rightful card holder.