transfer AT&T landline number to an already existing Xfinity home line.

Hello user_nz7l3w, thank you for reaching out here in our Xfinity Community forum. We are happy you're here, and happy to help. I am happy to tell you, yes, your active ATT number can be ported to your active Xfinity Voice phone line. You can call in to customer care at 800-266-2278, or we can assist you here if you wish. Just let us know which option you prefer, and we will provide the next steps for you.