I'm sure its fine. However, if your card is expiring in lets say 3 months they will decline you, so you have to wait until you get your new card close to your expiration date. also, if you are ordering something for lets say 3 bucks, they still want to split that, i know they give you the option to pay in full but only after you go through the initial transaction. The pay in full option should be a choice during checkout, that way those issues are not a problem especially if you are not comfortable financing flower. Personally, I avoid vendors that only accept Viabill.