Direct Answer
To hire a reliable window replacement contractor in St. Louis: (1) Get 3 written quotes with line-item breakdowns, (2) Verify MO license at Missouri Division of Professional Registration (pr.mo.gov), (3) Confirm active general liability and workers' comp insurance, (4) Check Google and BBB reviews specific to St. Louis projects, (5) Never pay more than 10-30% upfront — never pay in full before completion.
Full Explanation
Red flags specific to St. Louis contractors: no physical St. Louis-area address, pressure to start immediately, cash-only payment demands, and license numbers that don't verify at Missouri Division of Professional Registration (pr.mo.gov). Seasonal demand during summer brings out less reputable contractors.
Local Factors in St. Louis
📍Verify license: Missouri Division of Professional Registration (pr.mo.gov)
📍File complaints: Missouri Division of Professional Registration (pr.mo.gov)
📍Homeowner protections under MO consumer protection law
📍BBB Greater St. Louis chapter for complaints history