new address; forwarding address
Refers to the address one moves to, often used when notifying others of a change of address.
Please tell me your new address.
移転先に郵便物を転送してもらう。
I have my mail forwarded to my new address.
住所変更 is the act of changing one's address, while 移転先 refers to the new address itself.
Compound of 移転 (iten, 'moving, relocation') and 先 (saki, 'destination, place').