Carstens Construction CO, B General Building Contractor in San Mateo, CA
Carstens Construction CO operating as a corporation holds an active California contractor license (CSLB #305427), valid through Mar 31, 2028. First issued in 1975, the license has been on the CSLB roster for 51 years. It carries a single CSLB classification: B — General Building Contractor. Records show an active surety bond on file with Nationwide Mutual Insurance Company and an exempt workers' compensation status (no employees on payroll). The business is based in San Mateo, in San Mateo County, California.
- License Number
- 305427
- Issued
- May 12, 1975
- Status
- CLEAR
- Expires
- Mar 31, 2028
- Entity
- Corporation
- Surety
- Nationwide Mutual Insurance Company
- Bond Number
- 7901280658
- Effective
- Sep 1, 2025
- Status
- Active
- Coverage
- Exempt
- Carrier
- —
- Policy Number
- —
- Effective
- Mar 24, 2026
- Expires
- —
This contractor warrants a closer look before contracting:
- Workers' comp listed as exempt
An automated summary of public CSLB data, not a credit score, rating, or endorsement. How we determine this
Is Carstens Construction CO licensed in California?
Yes. Carstens Construction CO holds California Contractors State License Board license number 305427, which is active and in good standing. The license was first issued on May 12, 1975. It is valid through March 31, 2028.
What does Carstens Construction CO specialize in?
Carstens Construction CO is licensed for one CSLB classification: B General Building Contractor.
Where is Carstens Construction CO headquartered?
Carstens Construction CO is headquartered at 1206-A West Hillsdale Bl, San Mateo, CA 94403, in San Mateo County, California.
Does Carstens Construction CO have an active surety bond on file with CSLB?
Yes. Carstens Construction CO has an active California contractor surety bond filed with Nationwide Mutual Insurance Company.
Does Carstens Construction CO carry workers' compensation coverage?
Carstens Construction CO reports an exempt workers' compensation status, meaning the business has no employees on payroll.
How do I verify Carstens Construction CO's contractor license?
You can verify Carstens Construction CO's license directly with the California Contractors State License Board at https://www.cslb.ca.gov/OnlineServices/CheckLicenseII/LicenseDetail.aspx?LicNum=305427.
- License issuedMay 12, 1975
- Bond activeSep 1, 2025
- WC coverage startsMar 24, 2026
- License expiresMar 31, 2028
- R & W Concrete Contractors Incorporated#306552San Carlos·A General Engineering Contractor
- Forbes Construction#306687San Bruno·B General Building Contractor
- Amcal Construction Property Maint. CO#307161Redwood City·B General Building Contractor
- Door Thomas L#303165San Mateo·B General Building Contractor
- Imbelloni Construction CO INC#304975San Mateo·B General Building Contractor
- Keiser Ross General Contractor#304973Half Moon Bay·B General Building Contractor
- Wasmann J R Construction CO#297783San Mateo·B General Building Contractor
- Grech R and Sons Construction#298426San Carlos·B General Building Contractor
Working a California job with Carstens Construction CO, or chasing an unpaid invoice? These free tools track your mechanics lien deadlines and rights under California Civil Code §§8200–8848.
- California preliminary notice deadline calculatorFind your 20-day deadline and the lien rights at risk.
- Do I need a preliminary notice in California?Answer a few questions to see if the 20-day notice applies.
- Did I lose my California lien rights?Check whether your mechanics lien window has passed.
- Unpaid construction invoice in CaliforniaYour options and deadlines for collecting on a California job.
Own Carstens Construction CO? Claim or correct this profile