If you receive a “billing address does not match” error while adding a credit card in the Kasa app, it means that the information you entered may not be verifying correctly with your credit card’s issuing bank. TP-Link do not store the billing address information, all the payments will go through the payment gateway, processed by the card-issuing bank If your payment card is declined by the payment gateway, please kindly check the following tips. Ensure that there are no missing characters or misspellings in the name and address you entered and that the card number you entered is correct. Double-check the zip code and ensure it matches the one it has on file. Please contact your bank to check what the card-issuing bank has on file if necessary. Try to use another credit card if available. If you need further assistance, please contact TP-Link Technical Support Here.