Each state has different requirements for HVAC technicians to receive a license, but some common certifications that technicians must have are the North American Technician Excellence certification, HVAC Excellence certification and EPA 608 certification. Many states require HVAC technicians to get a general or mechanical contractor license. Some states, such as Missouri, Minnesota and Pennsylvania, require no license.
For most states, license requirements include past supervised experience, proof of insurance and the ability to pass exams. Most states require a fee to obtain a license and an annual renewal fee.
While the North American Technician Excellence isn't required to become an HVAC technician, it is a generally recognized certification among professionals. The EPA 608 certification is required by all people who have access to refrigerants, and professionals cannot purchase refrigerants without it.