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California contractor license

1 Backflow Plumbing

1 Backflow Plumbing of San Francisco holds California license 807692 (B General Building, C36 Plumbing). The CSLB file dated Oct 26, 2026 lists it as active.1 It expires May 31, 2028.

Doing business as Cat Builders Inc.

Licensed 24 years, longer than 78% of 250 active San Francisco plumbing contractors.

Active

1 Backflow Plumbing, San Francisco

License
807692
Class
B General Building; C36 Plumbing
Expires
May 31, 2028
Bond
$25,000
Workers' comp
Insured to Mar 17, 2027

CSLB file dated Oct 26, 2026

What bond, insurance and workers' comp are on file?

Bond
$25,000Jet Insurance Company, from Oct 2, 2026, continuous
Liability insurance
Not in the CSLB fileCheck with the board
Workers' comp
InsuredTechnology Insurance Company Inc, from Mar 16, 2026, to Mar 17, 2027

What work does this license cover?

Issued May 6, 2002.

Which other San Francisco businesses hold B General Building?

Plumbing Contractors in San FranciscoCalifornia plumbing contractorsGeneral Contractors in San FranciscoCalifornia general contractors

What should you check before hiring?

What to ask before you hire

  1. Get the license number in writing. The name on the license should match the name on your contract and invoice.
  2. Check the class covers the job. A license for one trade doesn't cover another. California license classes
  3. Ask for a certificate of insurance sent to you by the insurance agent, not handed over by the contractor. How to read a COI
  4. Ask who will be on site. If a crew works on your property, ask for proof of workers' comp. An exemption on file means the contractor told the CSLB it has no employees.
  5. Put it in a written contract: license number, price, start date and payment schedule. Check the license again on the day you sign.

If the license is lapsed

  1. Don't sign or pay a deposit until the CSLB shows the license active again.
  2. Ask the contractor why. For a bond or insurance lapse, ask for proof that the new bond or policy was filed with the CSLB, then check again.
  3. If work has started, hold further payments, keep the contract, receipts and photos, and file a complaint with Contractors State License Board (CSLB).
  4. Check another contractor. California license lookup

Sources

  1. CSLB License Master (cslb.ca.gov, Oct 26, 2026)
  2. Contractors State License Board (CSLB)