A written estimate is the first real test of whether a contractor operates professionally. Before you compare price, compare structure.
Look for a breakdown, not a single number. A trustworthy estimate separates labor, materials, permits, and disposal. If everything is bundled into one lump sum, ask why — it makes it much harder to spot padding or to compare one bid against another.
Check that the scope of work is specific. "Replace kitchen faucet" is not the same as "Remove existing faucet, install customer-supplied Moen fixture, replace supply lines, test for leaks." Vague scope is where change orders and surprise charges come from later.
Confirm what happens if the job changes. Ask directly: if they open a wall and find old wiring or water damage, how is that priced and communicated? A contractor who has a clear answer ready has done this before.
Ask about payment schedule. A standard, defensible schedule ties payment to completed milestones, not a large deposit up front with little tied to actual progress. Local and state rules on deposit limits vary, so ask what's typical in your area.
Get it in writing, always. A verbal promise about "what's included" means nothing once the invoice arrives. If it isn't on the estimate, it isn't guaranteed.
None of this replaces trusting your gut about a contractor's communication and professionalism — but a clear, specific, itemized estimate is one of the most reliable early signals you have.