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C55 Water Conditioning License (California)

California has 301 active C55 Water Conditioning holders in the state file as of 2026-10-29¹, the 60th-largest of 64 classes with at least 200 holders. 12 of them expire by 2026-12-28.

Active holders: 301; 0.1% of active California licenses
Expiring by 2026-12-28: 12; 4.0% of holders
Median bond on file: $25,000; 301 bonds
Workers' comp exempt: 40.9%; of 301 with WC status

How many C55 contractors are exempt from workers' comp?

123 of 301 active C55 holders with a recorded status (40.9%) filed an exemption¹, against 48.7% across all California classes.

How do you check a C55 license?

Search by license number or business name on the California license lookup, which reads the same state file.

Other California license classes

C22 Asbestos Abatement316
D39 Scaffolding288
C28 Lock and Security Equipment364
D16 Hardware, Locks and Safes274
D41 Siding and Decking414
C50 Reinforcing Steel254
D42 Non-Electrical Sign Installation422
C11 Elevator210

All 64 classes

Sources

CA CSLB License Master (cslb.ca.gov data portal) (cslb.ca.gov, 2026-10-29)