Vetting and Interviewing Subcontractors

Finding potential subcontractors is step one. Vetting them thoroughly before you hire is step two, and it's arguably more important. This is where you catch problems before they cost you money.

Poor vetting leads to: unlicensed contractors, uninsured workers, inexperienced subs, and problem contractors who seemed fine until you hired them. Thorough vetting catches these issues early and saves you thousands in delays, rework, and legal problems.

This guide will show you exactly how to vet subcontractors like a professional GC, what questions to ask, what documents to verify, and what red flags to watch for.

Why Vetting Matters

The cost of poor vetting:

The benefit of thorough vetting:

Time investment: 3-5 hours per contractor to vet properly

ROI: Saves thousands in prevented problems

The Complete Vetting Process

Follow this systematic approach for every subcontractor:

Phase 1: License Verification (Non-Negotiable)

Why it matters:

How to verify:

  1. Get the license number

    • Ask the contractor directly
    • Should provide immediately without hesitation
    • Get the exact license number and type

  2. Verify with state licensing board

    • Call or check online
    • Verify license is current (not expired)
    • Check license type matches work (electrical, plumbing, general contractor, etc.)
    • Verify name matches
    • Check for any disciplinary actions

  3. Ask for a copy

    • Request photo copy of license
    • Keep in your records
    • Some states require posting on job site

Where to check (varies by state):

Red flags:

Deal breakers:

What to know about licensing:

Exceptions:

Phase 2: Insurance Verification (Equally Non-Negotiable)

Why it matters:

Required insurance types:

  1. General Liability Insurance

    • Minimum: $1,000,000 per occurrence
    • Preferred: $2,000,000 per occurrence
    • Covers property damage and injuries
    • Protects you from damage to your project or neighboring property

  2. Workers' Compensation Insurance

    • Required if contractor has employees
    • Covers medical costs and lost wages for injured workers
    • Protects you from injury lawsuits
    • Sole proprietors may be exempt (varies by state)

How to verify:

  1. Request Certificate of Insurance (COI)

    • Ask contractor to have their insurance agent send you a COI
    • Should be sent directly from insurance company or agent
    • Don't accept certificates created by the contractor

  2. Verify the certificate

    • Policy holder name: Must match contractor's business name exactly
    • Policy dates: Must be current and cover your project timeline
    • Coverage amounts: Must meet minimums ($1M+ general liability)
    • Insurance company: Should be legitimate carrier (you can verify)
    • Agent contact info: Call to verify if questionable

  3. Check for "Additional Insured" status

    • You should be listed as additional insured
    • Provides extra protection
    • Costs contractor nothing to add
    • Makes claims process easier

  4. Verify with insurance company

    • Call the insurance company or agent listed
    • Confirm policy is active
    • Confirm coverage amounts
    • Confirm policy holder name

Red flags:

Deal breakers:

Special cases:

Phase 3: Reference Checking (Most Skip This - Don't)

Why it matters: Past performance predicts future performance. References reveal quality, reliability, communication, and how they handle problems.

How many references: Minimum 3, preferably 5

What kind of references: Recent projects (within 12 months) similar to yours

How to check references (don't skip this):

Call Every Reference

Why call vs. email:

When to call:

Questions to ask references:

  1. "What work did [contractor] do for you?"

    • Verify it matches what they told you
    • Confirm scope and scale

  2. "Were they on time for the start date?"

    • Tests reliability
    • Good contractors honor commitments

  3. "Did they finish when they said they would?"

    • Most critical question
    • Pay attention to any hesitation

  4. "Did the work pass inspection on the first try?"

    • For permitted work only
    • Reveals quality and code knowledge

  5. "How was their communication during the project?"

    • Did they return calls/texts?
    • Did they keep you informed?
    • Any surprises or hidden costs?

  6. "Were there any problems, and how did they handle them?"

    • Everyone has problems
    • What matters is how they respond
    • Did they own mistakes?
    • Did they make them right?

  7. "Was the final cost close to the quote?"

    • Tests honesty and estimating accuracy
    • Legitimate changes are normal
    • But consistent underestimating is a red flag

  8. "How was the quality of the finished work?"

    • Are they happy with results?
    • Has work held up over time?
    • Any callbacks needed?

  9. "Would you hire them again?"

    • Most important question
    • Listen for any hesitation
    • "Yes, absolutely" vs. "Yeah, I guess"

  10. "Is there anything you wish you'd known before hiring them?"

    • Opens up honest feedback
    • May reveal issues not covered above
    • Pay attention to what they volunteer

What to listen for:

Red flags in reference calls:

Green flags:

Ask to Visit Past Projects

Why it's valuable:

How to request:

"Would it be possible to see one or two of your recent projects? I'd love to see your work quality firsthand."

What to look at:

Questions to ask homeowner during visit:

Red flags:

Phase 4: Background Research

Online presence check:

  1. Google the business name

    • Look for website, social media
    • Check Google reviews (but with skepticism)
    • Search "[contractor name] complaints"
    • Search "[contractor name] lawsuit"

  2. Better Business Bureau (BBB)

    • Check for complaints
    • Look at complaint resolution
    • Rating is less important than how they handle issues

  3. Court records (if accessible)

    • Search for liens filed by or against contractor
    • Check for lawsuit history
    • Multiple lawsuits is a red flag

  4. State licensing board complaints

    • Most boards show complaint history
    • Look for patterns
    • One complaint may not mean much
    • Multiple complaints or serious violations are concerning

What to look for:

Red flags:

Phase 5: The Interview

Format: Phone call first, then in-person if they pass

Location for in-person:

Who should attend:

Duration: 30-60 minutes

What to bring:

Questions to Ask in Interview

About their business:

  1. "How long have you been in business?"

    • Looking for 2+ years minimum
    • Established is better for new construction

  2. "What percentage of your work is new construction vs. remodeling?"

    • Make sure they're experienced in new construction
    • Different codes and processes

  3. "How many projects do you typically have going at once?"

    • Too many = you won't get attention
    • Too few = may be struggling
    • 2-5 active projects is normal

  4. "Who will actually be doing the work?"

    • The person you're talking to?
    • Employees?
    • Subcontractors?
    • Will you meet them before hiring?

  5. "Do you have experience working with owner-builders?"

    • Some contractors prefer not to
    • Better to know upfront
    • Ask about any special requirements

About the project:

  1. "Have you done similar projects in the past year?"

    • Ask for specifics
    • Should mention 2-3 easily

  2. "Do you see any challenges with my project?"

    • Tests problem-solving
    • Shows they reviewed your plans
    • Identifies issues early

  3. "What's your typical timeline for a project like this?"

    • Compare to your expectations
    • Too fast may be unrealistic
    • Ask what factors affect timeline

  4. "How do you handle code inspections?"

    • Should say they build to code
    • Should know inspection schedule
    • Should have good pass rate

  5. "What's your inspection pass rate?"

    • Great contractors: 90-100% first-time pass
    • Good contractors: 80-90%
    • Concerning: Below 80%

About process and communication:

  1. "How do you prefer to communicate during the project?"

    • Phone, text, email?
    • How often?
    • Will they provide updates?

  2. "What do you need from me to do your job well?"

    • Shows they've thought about working with you
    • Tells you what to expect
    • Sets up success

  3. "How do you handle changes or unforeseen issues?"

    • Everyone encounters issues
    • Process for documenting and pricing changes?
    • Communication about problems?

  4. "What's your warranty/callback policy?"

    • Will they fix issues after completion?
    • What's covered and for how long?
    • How do you reach them for callbacks?

About scheduling and payment:

  1. "When would you be able to start?"

    • Compare to your timeline
    • Too immediate is a red flag
    • Should book 4-12 weeks out

  2. "How long would this project take from start to finish?"

    • Get specific timeline
    • Ask about factors that could delay
    • Understand dependencies

  3. "What's your payment structure?"

    • Should be progress-based
    • Deposit should be 10-20% max
    • Final payment after completion and inspection

  4. "Do you require a deposit, and how much?"

    • 10-20% is standard
    • 30%+ is a red flag
    • 50%+ is a major red flag

About materials and methods:

  1. "Do you provide materials, or do I purchase them?"

    • Varies by contractor
    • Understand who's responsible
    • Affects payment structure

  2. "What brands/products do you typically use?"

    • Shows quality standards
    • Can research products
    • Opportunity to discuss preferences

  3. "How do you handle site cleanup?"

    • Daily cleanup?
    • Who provides dumpster?
    • Final cleanup included?

About problems (important):

  1. "Tell me about a project that didn't go as planned. What happened and how did you handle it?"

    • Everyone has problem projects
    • What matters is how they handled it
    • Refusal to discuss is a red flag

  2. "What happens if I'm not satisfied with the work?"

    • How do they handle complaints?
    • Willing to make things right?
    • Process for resolving disputes?

What to Observe During Interview

Body language and demeanor:

How they discuss your project:

Red flags during interview:

Green flags:

Phase 6: Site Visit (If Possible)

Visit an active job site (with permission):

What to look for:

Red flags at job site:

Green flags:

The Decision Matrix

Rate each contractor on these factors (1-5, with 5 being best):

Contractor Decision Matrix - Rate Each Factor
FactorWeightContractor AContractor BContractor C
License verifiedMust havePass/FailPass/FailPass/Fail
Insurance verifiedMust havePass/FailPass/FailPass/Fail
ReferencesHigh453
ExperienceHigh544
CommunicationHigh453
PriceMedium345
AvailabilityMedium534
Professional demeanorMedium453
Code knowledgeHigh553
**Total****30****31****25**

Must-haves (pass/fail):

If they fail any must-have, eliminate them regardless of other factors

Weighting:

Making the decision:

Common Vetting Mistakes

1. Skipping License Verification

The mistake: Taking their word for it that they're licensed

Why people do it: Seems awkward, takes time, trust the person

The cost: Unlicensed work fails inspection, must tear out and redo

How to avoid: Make it standard practice, verify every contractor

2. Not Calling References

The mistake: Reading online reviews instead of calling references

Why people do it: Calling feels awkward, online reviews seem sufficient

The cost: Miss red flags that references would have revealed

How to avoid: Call at least 3 references, every time

3. Accepting Homemade Insurance Certificates

The mistake: Taking a certificate from the contractor instead of from insurance company

Why people do it: Seems official, easier than verifying

The cost: Certificate is fake, you have no coverage, liable for injuries

How to avoid: Require COI sent directly from insurance company or agent

4. Hiring Based on Price Alone

The mistake: Choosing the lowest bid without thorough vetting

Why people do it: Budget pressure, want to save money

The cost: Low bidders often create expensive problems

How to avoid: Vet thoroughly regardless of price, eliminate extreme high and low bids

5. Not Meeting in Person

The mistake: Hiring based on phone calls and emails only

Why people do it: Saves time, seems efficient

The cost: Miss important red flags visible only in person

How to avoid: Always meet finalists in person before hiring

6. Ignoring Your Gut

The mistake: Hiring someone who gives you bad vibes because they check other boxes

Why people do it: Can't articulate the concern, seems irrational

The cost: The concern was usually valid

How to avoid: Trust your instincts, there are other contractors

Vetting Checklist

Use this for every subcontractor:

License Verification

Insurance Verification

Reference Checking

Background Research

Interview

Final Decision

Red Flags Summary

Never hire if:

Proceed with caution if:

Questions to Ask Yourself

Before hiring any contractor:

  1. Did they pass all must-have requirements (license, insurance, references)?
  2. Do I feel confident in their ability to do quality work?
  3. Do I trust they'll show up and finish?
  4. Am I comfortable with how they communicate?
  5. Is their price fair (not necessarily lowest)?
  6. Does my gut tell me this is the right contractor?

If you answer "no" to any of these, keep looking

Next Steps

Once you've thoroughly vetted your contractors:

  1. Get Quotes → - Request detailed quotes from your top 2-3 vetted contractors

  2. Create Contracts → - Protect yourself with proper written agreements

  3. Payment Structure → - Understand when and how to pay

**Remember