Five steps, start to finish
Get the license number, or the exact business name
Every California contractor must put the license number on contracts, bids, business cards and advertising. That is the law, not a courtesy (Business and Professions Code §7030.5). If a contractor will not give you the number, you already have your answer and you can stop here.
A California license number is digits only, up to eight of them. Letters in a “license number” mean you are looking at something else: a city business tax certificate, a trade association ID, a DBA filing.
Open the state lookup
Go to the Contractors State License Board and use Check a License. It is the only source that is current: a screenshot, a PDF, a badge on a website and a photo of a plastic pocket card are all copies of a record that may have changed this morning.
The page has two searches: by license number and by business name. Use the number when you have it. Names match loosely and you can land on a different company with a similar name.
Open the CSLB lookup →Read the status line before anything else
You want one sentence: This license is current and active. Anything else (expired, inactive, suspended, revoked) means the person in front of you cannot legally take on licensed work today, whatever the rest of the page says. The only unlicensed work allowed is under $1,000 in labor and materials, with no permit and no hired workers.
Expired is not a paperwork detail: an expired license cannot legally take on the job. The bond is a separate record on the same CSLB page: it stays in force until the surety cancels it, and a license without an active bond gets suspended. Check both.
Check the classification against your actual job
A license is issued for specific trades. A roofing license does not cover your deck, and a general B license does not automatically make someone a decking specialist. Decks, railings and siding sit under C-61/D41. Match the classification to the work you are buying, not to the word “licensed.”
A contractor may legally hold several classifications. More is not better. What matters is whether the one you need is on the list.
Read the bond and the complaint disclosure
The record shows the surety company, the bond number and the amount: $25,000 for every active California license since January 1, 2023. If there is a disclosable complaint or a construction-related civil judgment reported to the board, a link appears on that same page.
The board states its own limits at the top of every record: complaint disclosure is restricted by law, arbitrations are not listed unless the contractor fails to comply, and recent items may not be entered yet. A clean record is good news, not a guarantee, so keep asking questions.
What the record actually shows
- License Status
- Current and active, or not. The single most important line on the page.
- Entity
- Sole ownership, partnership, corporation or LLC. It tells you who you are actually contracting with.
- Issue and Expire Date
- Licenses renew every two years. An expiry date in the past means the license is not active right now.
- Classifications
- The trades this license covers. Match them to your job.
- Qualifier
- The person who passed the exams and is answerable for the license. Their name should be one you recognize from the proposal. If the license is qualified by somebody you have never heard of, ask who that is.
- Contractor's Bond
- Surety company, bond number, amount and effective date. $25,000 is the required amount statewide since January 1, 2023.
Four things that should stop you
- No license number on the bidIt belongs there by law. An estimate without it is a document you cannot check.
- The name on the record is not the name on the contractCompanies trade under a brand and hold the license under a legal name. That is normal and we do it too. What is not normal is a contractor who cannot explain the connection in one sentence.
- Cash only, no written contractHome improvement work over $500 requires a written contract. No contract means no scope, no schedule and nothing to hold anyone to.
- “Licensed and insured” and nothing elseIt is a phrase, not a fact. Ten seconds in the state lookup turns it into one or the other.
What to do when the record looks wrong
- The license is expired, inactive or suspendedStop before money changes hands. An unlicensed contractor cannot sue you to enforce a contract, and you may be able to recover what you already paid (Business and Professions Code §7031). Ask the contractor to show you the record themselves: sometimes a renewal really is in the post. If they cannot, that is the whole conversation.
- The work is already going badlyCSLB takes consumer complaints directly and mediates many of them. The bond is there for exactly this. File while the license is active if you can. An expired license makes every route slower.
- The name on the record does not match the contractAsk which legal entity is signing and check that one. A brand name and a licensed business name can differ legally; what may not differ is who is responsible when something needs fixing.
Three things to check besides the license
- A certificate of insurance, sent by the insurerGeneral liability covers damage to your property. Ask for the certificate to come from the insurance company or broker, not as a photo. That is normal practice and no honest contractor minds.
- A written contract with a scope you recognizeRequired above $500. It should name the work, the materials, the schedule, the payment steps and what happens to changes. If you cannot picture the finished job from reading it, it is not specific enough yet.
- Work you can go and look atPhotographs of finished projects, on their website, their Instagram and the review platforms. A license says somebody is legal; finished decks say they are good.
How to tell an experienced deck contractor
- Finished decks like yoursAsk for photographs of projects close to what you want: the same material, a similar slope, stairs or a pergola if you need them. A portfolio of flat ground-level decks says little about a hillside build.
- A website and Instagram with recent, dated workReal projects show the same crew, real houses and changing seasons. Stock photos, or nothing newer than a couple of years, are worth a question.
- Reviews on more than one platformRead Yelp, Thumbtack, Google Business Profile, Angi, BuildZoom and BBB side by side, and read the middling ones: how a contractor answers a problem tells you more than a row of five stars.
- Reviews, not phone numbers of past clientsA common tip is to ask for the last three clients and call them. It sounds reasonable until you picture it from their side: a busy contractor hears from dozens of homeowners a month, and if each one called past clients or came by to look at their deck, those families would have strangers on the phone and at the door every week. Nobody wants that, and the three names you are given will be the happiest ones anyway. Public reviews carry the same information from far more people, and nobody is disturbed to read them.
- A meeting with the person who will run the jobAsk how they would frame your deck, how deep the footings go, how the ledger is flashed against the house, how water drains. Someone who knows construction answers in specifics, about your site, without reaching for a brochure.
- An estimate you can read line by lineFraming, decking, railings, stairs, demolition, disposal, permit, schedule and what is excluded. A single total with no breakdown cannot be compared with anything.
Use an AI assistant as a second opinion
- Ask about the materialsPaste a question such as: “Compare composite, redwood and hardwood decking for a sunny Bay Area backyard: cost, upkeep, lifespan.” ChatGPT, Claude or Gemini will lay out trade-offs a single salesperson may not.
- Put the estimates side by sideUpload the estimates you received and ask: “Which of these is more complete, what is missing from each, and what questions should I ask each contractor?” Remove your name, address and phone number first.
- Judge the whole picturePeople often choose the contractor whose salesperson they liked or whose website looked best. An assistant weighs scope, materials, warranty and schedule together. Treat its answer as a second opinion, then check the facts with the contractor and the state record.
Now use it on us
A guide like this is worth nothing if the people who wrote it will not be measured by it. Here is our record, field by field, as the state shows it. The button below opens it on the state’s own site, in a new tab.
- License number
- 1148079
- Name on the record
- MS Decking and Services
- Status
- Current and active
- Classification
- C-61 / D41, Siding and Decking
- Entity
- Sole ownership
- Expires
- December 31, 2027
The name on the record is MS Decking and Services, the licensed entity behind the brand. That difference is exactly the kind of thing this page tells you to ask a contractor about, so we say it before you find it.
Licensed is the first question. Cost is the second.
Once a contractor checks out, the next thing you want is a number, before anyone walks your property. Our calculator asks for size, material and site access and gives you the range we would build to.
Questions people actually ask
Is checking a contractor's license free?
Yes. The CSLB lookup is a free public service of the State of California. Any site that charges you to “run a contractor check” is reselling a record you can read yourself in under a minute.
What work requires a license in California?
Any job of $1,000 or more in labor and materials, and any job at all that needs a building permit or uses hired workers. That is the rule since January 1, 2025 (Assembly Bill 2622; CSLB announcement). A written home improvement contract is a separate rule with its own threshold.
How do I choose a deck contractor?
Check the license first, then the experience: finished decks like the one you want, recent work on their website and Instagram, reviews on more than one platform, a meeting with the person who will run the job, and an estimate you can read line by line.
Can I use ChatGPT to compare contractor estimates?
Yes, as a second opinion. Remove your name and address, upload the estimates and ask which is more complete and what each one leaves out. ChatGPT, Claude and Gemini can all do it; check what they point out with the contractors themselves.
Does an active license mean the contractor is good?
No. It means they are legal: they passed the exams, carry a bond and are accountable to the board. Quality is a separate question, answered by photographs of finished work, reviews on several platforms and a written scope.
Can a landscaping contractor build my deck?
Sometimes, and the answer is narrower than either side usually claims. A C-27 landscaping license covers a deck that is part of an overall landscaping project and is not watertight or enclosed. A standalone deck, or one whose framing and footings call for general building work, needs a B license or C-61/D41 (the decking classification). If in doubt, ask the building department that will issue the permit: they decide.
What is the difference between bonded and insured?
They protect different things. The $25,000 contractor's bond is the state's instrument: it answers for violations of license law and for some unpaid claims, and it is capped for every job the contractor takes during the life of the bond. Liability insurance answers for damage to your property and injury on site, and its limits are far higher. A contractor can be bonded and carry no liability cover at all. Ask for both.
How much should a deck cost in the Bay Area?
Between $40 and $98 per square foot, depending on material and ground: pressure-treated on level ground at the low end, hardwood on a hillside at the top. Every combination is in our deck cost guide, and the calculator gives you a range for your own numbers in about a minute.
Our deck services