Just did UA TB for an Aspire ($50 x 1) and several Biz Plats ($100 x 2 each). For most purchases I correctly typed the 4 digit CVV on the back of the card which worked fine. For one purchase I inadvertently typed the 3 digit CVV on the back of a biz plat, worked fine. I typed the 3 digit CVV again, worked fine again. For one purchase I left the CVV field blank, worked fine.