The only time an AVS(Address Verification Service) check is done is when a payment is being authorized. Since subsequent gifts are using the initial token, this is not being done for each following charge. The exceptions to this are if a new card is added to the gift, or if a Sustainer Migration is being done by Luminate staff to move things over to a new Merchant Account. In both scenarios the payment method needs to be authorized again, which triggers another AVS check.