How we vet
Five checks, in the order a homeowner can do them. A company that fails the first two is out, no matter how good the reviews are.
License
If Texas licenses the trade, the company and the person on site hold a current license, and the number is on the truck, the invoice and the website. Plumbing is verified at TSBPE; electrical and air conditioning at TDLR. Roofing and foundation repair have no Texas license, so this check becomes a check for trade association membership and manufacturer certifications.
Insurance
A certificate of insurance for general liability, issued to you by the insurer or agent, not a photocopy from the contractor. Texas does not require private employers to carry workers' compensation, so ask whether they do. If they do not, an injured worker can look to you.
Permits
Work that the City of Houston requires a permit for gets one, pulled by the contractor in the contractor's name, with an inspection. A contractor who asks you to pull the permit as the homeowner is usually hiding a license problem.
Scope and price in writing
A bid names the work, the materials by brand and grade, what is excluded, the warranty in years, and the payment schedule. A total with no scope is not a bid. Large deposits before materials arrive are a warning sign.
Track record
A verifiable history: years under the same name, a street address, reviews that describe specific jobs, and references you can call. Companies that change names after bad reviews do not pass.