Key Takeaways
- Always verify a contractor's license and insurance before signing anything or paying a deposit.
- Get at least three written bids to understand fair market pricing for your project.
- A signed, detailed written contract is your most important protection against disputes.
- Never pay more than 10–30% upfront; avoid contractors who demand full payment before work begins.
- Permits are often legally required — confirm who is responsible for pulling them before work starts.
Summary
22 items · 30–60 minutes
Why Vetting a Contractor Matters Before You Commit
Hiring the wrong contractor is one of the costliest mistakes a homeowner can make. Incomplete work, unresolved code violations, and disputes over payments are all far easier to prevent than to fix after the fact. Whether you're planning a kitchen remodel, a roof replacement, or a bathroom addition, the time you spend vetting candidates upfront pays dividends throughout the project.
If you're still deciding whether this project is even a DIY candidate, see our guide to choosing between DIY and hiring a pro before going further. Once you've decided to hire out, use the checklist below to make sure every contractor you consider meets a minimum standard of legitimacy and professionalism.
License and Insurance Verification
Reputation and References
Written Bids and Scope of Work
Contract Terms and Payment Structure
Red Flags to Watch For
Tools and Documents You'll Need During This Process
Before you start making calls, gather a few resources that will make your vetting process faster and more reliable. Some of these take only minutes to access online, but they can reveal critical information before you invest any more time in a candidate.
State Contractor Licensing Board Website
Verify that a contractor's license is active, current, and free of disciplinary actions in your state.
Certificate of Insurance (COI)
Confirms the contractor carries active general liability and workers' compensation coverage — request this document directly from the contractor.
Written Project Scope / Itemized Bid
A line-by-line breakdown of materials, labor, and exclusions that lets you make an accurate comparison across multiple bids.
State Attorney General Consumer Protection Lookup
Search for complaints or enforcement actions filed against a contractor's business name in your state.
Local Building Department Contact
Confirm which permits are required for your project type and verify that permits were actually pulled once work is underway.
Lien Waiver Template
A document signed by the contractor and any subcontractors confirming they have been paid and waive the right to place a mechanic's lien on your property.
Understanding Bids and Contracts
Once you've confirmed that a contractor is licensed and insured, the next critical step is comparing written bids. A verbal quote is not enough — you need itemized, written estimates from at least three contractors to gauge fair pricing and scope coverage. Our companion article on reading a contractor's bid walks you through what each line item means and where hidden costs tend to appear.
Pay close attention to how each bid handles allowances (budget placeholders for items not yet selected), exclusions (work explicitly not included), and change-order procedures (how cost increases are handled mid-project). A thorough bid protects both parties and leaves little room for surprise charges later.
Don't Skip the Permit Step
Many homeowners don't realize that unpermitted work can void homeowner's insurance claims, create problems when selling the home, and result in mandatory removal of completed work. Always confirm in writing which permits are needed and who is pulling them. If a contractor suggests skipping permits to save time or money, treat that as a serious red flag.
For a broader reference on when permits are legally required and which trades need licenses in your state, consult our homeowner's guide to permits, inspections, and licensed trades. Requirements vary significantly by municipality, so verify local rules directly with your building department.
Never Pay in Full Before Work Is Complete
Paying a contractor in full before a project is finished removes your most important form of leverage. If problems arise — incomplete work, no-shows, or substandard results — recovering money already paid is significantly harder than withholding a final payment. A milestone-based payment schedule keeps both parties accountable from start to finish.