My address used to be:

123/8 M.3 T.Maret
Koh Samui, Suratthani
Thailand 84721

Overseas, especially in hotels where your guests can be from anywhere, we would design our forms to be "flexible" anytime an address was involved. This gets tricky when you are trying to do mailing labels. I would follow a simple format:

Name
Address1
Address2
City
State/Province
Country
Zip

Then, the person entering the information should realize what will happen if the information gets shuffeled around. You might also look at a few web sites that accept international demographics to see what they are doing.

HTH