When are you allowed to use the symbol "TM"?
Hi there Rentmywindshield! I'm sure you will be a more "official" answer soon, but here's the quick answer. Just check to make sure the name or phrase is not already federally protected ( www.uspto.gov ) and if it is not, then you can start using TM right away. It's the (R) you can't use until you are federally registered.