General building contractor in Ontario, CA

45 licenses · checked Oct 27, 2026

There are 45 General building contractor licenses with an address of record in Ontario, CA, in the CSLB License Master data checked Oct 27, 2026. That is 0.3% of the 14,299 such licenses statewide; Ontario ranks #72 of 874 CA cities for this license type. They are spread across 3 ZIP codes; the most common are 91761 (23), 91762 (15), 91764 (7). Most list San Bernardino County. By business type: Corporation 27, Sole Owner 14, Limited Liability 3, JointVenture 1. The median first-issue year is 2017; the oldest license dates from 2015. 18 of them come up for renewal or expiration in the next 12 months, so re-check status before you sign a contract.

What a General building contractor license covers

General Building (B) covers framed structures for shelter or occupancy. A B contractor may take a prime contract for a project that involves at least two unrelated building trades, or framing/carpentry alone; plumbing, electrical or HVAC alone needs that specialty license or the B contractor must hold it.

How to verify a license

Enter the license number in CSLB Instant License Check and confirm the status is active, the classification matches the work, and the contractor has a current bond and workers' compensation coverage (or a valid exemption). California requires the license number on contracts and advertising. Official lookup: CSLB Instant License Check.

General building contractor licenses in Ontario

Showing 45 of 45, A to Z. Listing order is alphabetical, not a recommendation.

Frequently asked questions

How many General building contractor licenses are in Ontario?

45 active licenses in the CSLB License Master data checked Oct 27, 2026 (0.3% of CA).

What does a General building contractor license cover?

General Building (B) covers framed structures for shelter or occupancy. A B contractor may take a prime contract for a project that involves at least two unrelated building trades, or framing/carpentry alone; plumbing, electrical or HVAC alone needs that specialty license or the B contractor must hold it.

How do I verify a General building contractor license in Ontario?

Enter the license number in CSLB Instant License Check and confirm the status is active, the classification matches the work, and the contractor has a current bond and workers' compensation coverage (or a valid exemption). California requires the license number on contracts and advertising. Use the license number shown here with the CSLB Instant License Check.

How many Ontario General building contractor licenses expire soon?

18 of 45 have an expiration date in the next 12 months. A license that lapses must be renewed before the holder can work under it again.

Other license types in Ontario

Electrical contractor (C-10) (31) · General engineering contractor (16) · Painting contractor (C-33) (13) · HVAC contractor (C-20) (13) · Plumbing contractor (C-36) (10) · Low-voltage contractor (C-7) (9) · Landscaping contractor (C-27) (7) · Drywall contractor (C-9) (6) · Tile contractor (C-54) (4) · Cabinet and finish carpentry contractor (C-6) (4) · Flooring contractor (C-15) (3) · Concrete contractor (C-8) (3)

All General building contractor licenses in CA →

Source: CSLB License Master. Licensed California is independent and not affiliated with the licensing agency. Data checked Oct 27, 2026.