Is a manufacturer certification the same as a license?

No. Manufacturer certifications are commercial programs that can indicate training and can unlock extended product warranties, and they are not issued by a regulator and do not substitute for a license or for insurance.

Bonding is required in some jurisdictions and is a form of financial guarantee rather than insurance. It is worth asking about where it is required, and it does not replace liability cover or workers compensation.

Answers · Hiring a roofer

How do I check a roofing contractor is licensed and insured?

The short answer

Ask for the license or registration number and the exact legal entity it is held under, then check it with the licensing authority in the state or province where the work will happen — not where the company advertises. Separately, ask the insurer to send a certificate of insurance directly, covering liability and workers compensation.

Licensing varies, so check locally

Some states license roofing contractors specifically, some license general contractors above a value threshold, some regulate at city or county level, and some require registration rather than licensure. Canadian provinces differ again. There is no national register in either country, so the authority for your state or province is the answer, and a license held next door is not a license here.

Insurance is two separate things

General liability, which covers damage the contractor causes to your property.
Workers compensation, which covers their people if someone is hurt on your roof. Without it, an injured worker's route to compensation can run through the homeowner, and this is the one people skip.

Ask for the certificate to be sent by the insurance agent rather than handed to you by the contractor, and check the dates. A certificate is a snapshot and policies lapse.

Also asked

Is a manufacturer certification the same as a license?: No. Manufacturer certifications are commercial programs that can indicate training and can unlock extended product warranties, and they are not issued by a regulator and do not substitute for a license or for insurance.
What about a bond?: Bonding is required in some jurisdictions and is a form of financial guarantee rather than insurance. It is worth asking about where it is required, and it does not replace liability cover or workers compensation.

General information about roofs and about hiring, not advice about your building. Roofing contractor licensing, permits, insurance practice and deductible rules are set state by state and province by province across the United States and Canada, so your own authority is the current answer.