Perhaps a passport would do if you have one.

This is the off-topic part. We were in Maine several years ago and were eating in a fairly nice restaurant there. A group of tourists from Ireland were in there and wanted to order drinks. The waitress told them they'd have to show a driver's license and pointed to a sign on the wall. They offered their passports, but she said again that they'd have to have a driver's license. They finally got up in disgust and left. The point is that sometimes there's no common sense in "rules."