Do you have to have ID to get a tattoo?

A decent studio will ask for your ID before proceeding with the tattoo process. If they don't ask for your ID, they're a shady institution, and you don't want a tattoo from them.

Are you too young to get a tattoo? If so, just wait until you're old enough. It's not worth the risk of getting an ugly tattoo, or getting an infection from an unsterilized tattoo studio.

Do you just not have a driver's license or ID tag? Bring in some other kind of identification. It helps if it includes your photo. For example, a passport in conjunction with a birth certificate would work.