There was a fuss a while back over something like this. If I recall correctly, SE was blocking service accounts that were registered outside of the region they were being used. I'm not sure if you select a region when you set up your service account or if it's something that is done automatically based on which regional version of the game you have, but if I were you I'd get my info directly from the horse's mouth.
Contact SE and ask them to make sure. It's definitely a loss if you purchase a copy of the game you can't use at all.
*EDIT* Found some info
Square Enix wrote:
1. The screen below will appear immediately after logging in. Please select your region.
2. On the next screen, please select your country of residence.
3. After confirming that your region and country of residence have been correctly entered, complete the registration process.
* Please note that you cannot change your country or region after registration has completed. Failure to properly identify the correct region and country may cause you to be denied access to services.
I wouldn't touch that if I were you... Edited, Sep 19th 2012 2:06am by FilthMcNasty
Only hips + boobs all day and hips + boobs all over my icecream
Someone get me Ben and Jerry's on the phone...
FilthMcNasty: Troll flame tested, admin approved