What tests do you have to pass to become a vet tech?

Most states require that you have passed the Veterinary Technician National Exam and some even have a state board exam that must be passed. The exact requirements varies because each state sets it's own laws governing veterinary technicians.

To find the exact requirements for a given state, you should contact the governing body that credentials veterinary technicians. Or if you do not know who credentials veterinary technicians, contact the state veterinary technician association and they can help you find the information you are looking for.