Using an existing member's address to join the fan club

[achikochiniseri.livejournal.com]

Hi everyone! I would like to join Arashi's official fan club. I have a friend who lives there and is already a member. She sent me her address so I can use it too to sign up for membership. I heard there is a sponsorship system but I don't want to cause inconvenience to my friend that's why I just plan to sign up on my own and input her address. Do you think this is ok? I'd really appreciate your response. Thank you!