Transferring Accounts

[Mirage]

Then the answer is yes. I think.
Two persons can't log in with the same account at once though, nor can you transfer one character from one account to another.

I'm not sure I understand your question. When you say transfer account, do you mean quit playing on the Xbox360 to play on the PC or do you mean transfering characters between accounts?

The account you use on the XBox360 should be accessable on the PC. If you and your brother currently share an account, and you want to play together, then one of you will have to start over.

SE is a pain in the ass with transfers of characters from one account to another. It's happened before, but not often (I've only heard of it actually happening once). It's a poor business move on their part, but Square-Enix's customer support for FFXI is absolutely horrible anyway.

Either way, if you both want to be playing together at the same time, two accounts are absolutely necessary. Your brother might play on the PS2, but as soon as you log in under the same account on the PC, your brother will be disconnected. It's quite inconvenient for players, but very profitable for SE.

Quite usual too! If not, we'd have 10 complete strangers using the same account.