Check if a contractor is licensed.

Do not rely on a licence number printed on a quote. Verify it through the official state or local source.

Before paying: match the licence name to the quote, contract, invoice, and payment recipient.

What to verify

Licence number and official status.
Trade/classification: make sure it covers the work being quoted.
Expiration date and disciplinary history where available.
Business name match: licence, contract, invoice, website, and payment name.
Insurance and bonding, ideally confirmed from the insurer/agent.
Permit responsibility and written scope before work starts.

Run the company legitimacy checker before paying any meaningful deposit.