A licensed general contractor reveals the 5 sources you need to check before you hand over a deposit.
Why Should I Run a Background Check Before Signing a Contract?
Because a bad hire costs you $15,000-$50,000 in rework, delays, and legal fees. A background check takes 15-30 minutes. It is the cheapest insurance you will ever buy.
According to CSLB complaint data, the California Contractors State License Board receives over 20,000 complaints per year. About 3,500 of those result in formal disciplinary actions. Many of those contractors are still bidding on jobs today.
"As a contractor, I can tell you the three most expensive words in remodeling are 'I trusted him.' Trust is earned. Verification is free."
As a licensed GC who has completed hundreds of remodels, I see the same pattern over and over. The homeowner liked the contractor's personality. The bid looked reasonable. They signed without checking. Then the problems started. Missed deadlines. Vanishing acts. Change orders that doubled the budget.
The fix takes less time than brewing coffee. Check five sources before you sign. If you are comparing 3 bids (and you should be. Not two, not one, three), that is under 10 minutes per contractor.
How Do I Check a Contractor's CSLB License and Discipline History?
Go to cslb.ca.gov, enter their license number, and look for three things: active status, workers comp, and disciplinary actions. It takes 30 seconds.
Every licensed contractor in California has a public record on the CSLB website. Here is what matters:
License Status. Must say "Active." If it says "Revoked," "Suspended," or "Cancelled" - stop. Do not pass go. Do not sign that contract.
Workers Compensation. Should show insurance on file unless they are a sole owner with no employees. If they have a crew and no workers comp, you could be liable for job-site injuries on your property.
Contractor Bond. California requires a $25,000 contractor bond. Confirm it is on file.
Disciplinary Actions. This is the goldmine. CSLB lists every formal action - complaints, citations, and disciplinary orders. Zero is ideal. One might be explainable. Two or more is a pattern you cannot ignore.
Issue Date. A license from 2024 means 1-2 years of experience. A license from 2005 means they survived recessions, supply chain crises, and code changes. Both can be solid. The longer track record is just easier to verify.
In my experience building homes across Silicon Valley since 2017, about 1 in 4 contractors I have reviewed for homeowners had at least one CSLB filing they "forgot" to mention. The CSLB lookup finds what the sales pitch hides.
What Can Google and Yelp Reviews Tell Me That a Contractor Won't?
Reviews show you how a contractor treats homeowners after they get the job. The bid is the sales pitch. The reviews are the reality.
But you need to read them right.
Volume beats star rating. A contractor with 4.2 stars from 85 reviews is more trustworthy than a 5.0 from 6 reviews. Anyone can get family and friends to leave perfect stars.
Patterns beat outliers. Every contractor has one angry customer. What matters is whether the same complaint appears repeatedly. "Communication was terrible" in 4 different reviews? Pattern. "Tile shade was slightly off"? Outlier. Ignore it.
Recency matters. Great reviews from 2020-2022 and nothing since? The contractor may have changed crews, ownership, or quality. Look for consistent reviews within the last 12 months.
"As a contractor, I can tell you that the reviews I worry about most are the ones mentioning surprise costs and change orders. That is a contractor making up margin they left out of the original bid."
Google is your primary source. Google Business profiles show rating, review count, and sometimes photos of actual work. Yelp adds a second data point. Always check both.
If a contractor has no Google profile and no Yelp presence at all, that is a yellow flag. Not an automatic disqualifier. But combined with a license issued less than 2 years ago, it means you have very little to verify.
Should I Check Court Records and BBB Before Hiring a Contractor?
Court records are worth checking for any project over $50,000. BBB is fast and free but tells a narrower story.
Court records show whether a contractor has been sued by homeowners, subcontractors, or suppliers. A subcontractor suing a general contractor for non-payment is a major red flag. It means the GC may not be paying the people building your house. That puts a mechanic's lien on your property.
For California, most county superior courts have free online portals. The downside is you need to search each county separately. A contractor working across Santa Clara, San Mateo, and Alameda counties could have cases split across three systems.
BBB ratings are simpler. Check bbb.org for the letter grade, complaint count, and resolution history. An "F" rating with 12 unresolved complaints is an obvious avoid. But remember that BBB membership is voluntary and paid. An "A+" does not guarantee quality. It means they paid their dues and responded to complaints through the BBB process.
Here is what each source actually reveals:
| Source | What It Shows | What It Misses | Cost | Time |
|---|---|---|---|---|
| CSLB (cslb.ca.gov) | License status, workers comp, bond, discipline history | Work quality, customer satisfaction | Free | 2 min |
| Google Reviews | Customer ratings, review volume, photos, owner responses | Only covers customers who left reviews | Free | 3 min |
| Yelp Reviews | Detailed reviews, business details, response patterns | Yelp filter hides some legitimate reviews | Free | 3 min |
| Court Records | Lawsuits, liens, judgments filed against the contractor | Only covers the county you search | Free (most CA counties) | 5-10 min/county |
| BBB (bbb.org) | Letter grade, complaint history, resolution record | Voluntary membership, not comprehensive | Free | 2 min |
No single source tells the whole story. The power is in layering multiple sources and looking for consistent signals across all of them.
What Does a Complete Contractor Background Check Look Like in 2026?
A thorough check hits 5 sources and takes 15-30 minutes per contractor. For 3 bids, that is 45-90 minutes of work that could save you five figures.
Here is the full DIY checklist:
- CSLB Lookup (cslb.ca.gov) - 2 minutes
- Google Business Reviews - 3 minutes
- Yelp Reviews - 3 minutes
- County Court Records - 5-10 minutes per county
- BBB Lookup (bbb.org) - 2 minutes
That is 15-20 minutes per contractor if they operate in one county. Multiple counties means more time per court portal search.
Or you can automate most of it. Tools like Opsite's $49 Pro Report pull CSLB discipline history, Google reviews, Yelp data, and court records into a single background check with an overall trust verdict for each contractor. It also compares your bids line-by-line against market rates and gives you negotiation talking points. For a project where you are about to spend $45,000-$85,000 on a kitchen remodel or $100,000+ on an addition, $49 to verify who you are handing that money to is not even a rounding error.
| Factor | DIY (Manual Check) | Automated (Opsite Pro Report) |
|---|---|---|
| Cost | Free | $49 |
| Time per contractor | 15-30 minutes | Under 60 seconds |
| Sources checked | 5 (if you do all of them) | CSLB discipline, Google, Yelp, court records |
| Bid comparison included | You do the math yourself | AI line-by-line audit vs. market rates |
| Trust verdict | Your personal judgment | Scored 0-100 with full breakdown |
| Negotiation help | On your own | Talking points per contractor |
| Output format | Notes on paper | Printable PDF report |
Based on typical project data from Bay Area contractors, the homeowners who run background checks before signing report fewer disputes, fewer change order surprises, and significantly less stress during the build.
What Red Flags Should Immediately Disqualify a Contractor?
Some red flags are dealbreakers. No discussion, no second chances, no "but their price was the best."
Walk away immediately if:
- License is revoked, suspended, or cancelled on CSLB
- Two or more CSLB disciplinary actions
- Named as defendant in 3+ lawsuits
- No workers comp insurance and they have employees on the job
- They refuse to provide their license number
- Zero verifiable online presence combined with a license issued less than 2 years ago
Dig deeper (but do not auto-reject) if:
- One CSLB complaint that was formally resolved
- Low review count (under 10) but rating above 4.0
- One BBB complaint that was resolved
- License issued within the last 2 years (check references extra carefully)
- Workers comp exempt (sole proprietor with no employees)
"As a contractor, I can tell you that legitimate contractors are not afraid of background checks. We expect them. If a contractor gets defensive when you ask for their license number, that tells you everything you need to know."
From working with homeowners on projects ranging from $50K to $2M+, I have never once seen a dispute where the homeowner said "I'm glad I skipped the background check." The 15 minutes you spend checking could be the difference between a project you love and a nightmare that drains your savings.
Get your bids. Run your checks. Then sign with confidence. For more on protecting your payments after you sign, read our guide on what a draw schedule is and how it protects you.
Frequently Asked Questions
How much does a contractor background check cost?
A DIY background check using CSLB, Google, Yelp, and BBB is completely free. Court record searches vary by county, but most California portals are free. Automated tools like Opsite's Pro Report run $49 and aggregate multiple sources into one report with a trust verdict.
Can I run a background check on an unlicensed contractor?
You can check Google reviews, Yelp, BBB, and court records for any business. But if a contractor does not have a CSLB license, that is the biggest red flag of all. In California, any project over $500 requires a licensed contractor. Hiring unlicensed means no bond protection, no CSLB recourse, and no workers comp coverage if something goes wrong.
How long does a contractor background check take?
A manual check across all five sources (CSLB, Google, Yelp, court records, BBB) takes 15-30 minutes per contractor. An automated background check through a platform like Opsite takes about 60 seconds per contractor.
What if my contractor has one bad review?
One bad review is normal. Look at the overall pattern. A 4.5-star contractor with 60 reviews and one 1-star complaint is fine. Read the bad review carefully. If it mentions non-payment of subcontractors or permit violations, dig deeper. If it is about a paint color disagreement, move on.
Is a contractor required to give me their license number in California?
Yes. California law requires licensed contractors to include their CSLB license number on all advertising, contracts, and business cards. If a contractor will not share their license number, that is not just a red flag. It may be a legal violation.
Should I run a background check on subcontractors too?
Your general contractor manages the subs, but on larger projects over $100,000, it is worth checking the license status of major specialty contractors like electrical, plumbing, and HVAC. These trades require separate specialty licenses from the CSLB.
What is a contractor trust score?
A trust score is a 0-100 rating calculated from public data. Components typically include license status, workers comp coverage, contractor bond status, years in business, and discipline history. Opsite calculates trust scores automatically from CSLB data when you upload contractor estimates for comparison.
What should I do if the background check reveals serious problems?
If you find hard red flags like a revoked license, multiple lawsuits, or no workers comp insurance, drop that contractor immediately. If you find soft flags like one old complaint or a low review count, ask the contractor directly and verify their explanation against the public records. Always compare at least three bids so you have alternatives.