SSH-KEY in two accounts

Hello
i dont know if i'm doing this wrong, but, i have two bitbucket accounts:

1. from my work (company) to host our code here. sometimes i use my pc at home to do some work.
2. my personal account, with my own code.

now, i'm trying to add the ssh-key from my MBA to one of these accounts but it says "someone is already using this ssh-key"

so, i cannot give permissons to my pc in two differents accounts??

Thanks,
and sorry my bad english.