Expansion content is currently region locked depending on your PlayOnline account, not the SQUARE ENIX Account. If you have a NA PlayOnline Account, you will need to use a NA expansion code. The same would apply for any EU PlayOnline IDs. I hope this information was helpful and if you have any further questions in regards to this, please contact the SQUARE ENIX Support Center. Since this is not a technical issue with FINAL FANTASY XI, we have closed this thread.

The SQUARE ENIX Support Center for North American accounts can be found at this link:
SQUARE ENIX Support Center