Agreed on this advice. When I was new to AWS I kept receiving a bill for a few cents that obviously wasn't worth my time to resolve, but still really irritated my why I couldn't find a running instance. Turns out the running instance was in a different region and I didn't know the EC2 server list displayed only one region at a time.
Are you trying to protect your identity or just make sure the bill doesn't go over a set amount? If the latter then it shouldn't matter if ID is required.