Hello and welcome to the forum. You will definitely need to contact the business office to let them know of your change of address. ATT will need to verify the availability at your new location and activate the new service. I have included two links below. The first is a how to move your service link.
This second link is to send a private message to one of our ATTCustomer care representatives if you have any trouble our concerns on your move of service. Please include your name, email address, phone number and the best time to be contacted. Please allow up to 48hrs for a representative to contact you. Good luck with your move.