Washington: registration for nearly everyone, a separate ticket for plumbing
Washington requires anyone who contracts to do construction work to register with the Department of Labor & Industries. A registered general contractor can take on a bathroom remodel end to end and hire subcontractors for the parts it does not do itself. A specialty contractor is registered for one line of work only and cannot bring in subcontractors outside that specialty.[1]
There is a narrow exemption for work under 500 dollars total in labor and materials, as long as the person doing it is not advertising themselves as a contractor. Cross that line, or put up a sign, and the registration rules apply in full.[2]
Plumbing sits outside the general contractor registration entirely. A plumbing contractor license in Washington requires the business to employ a full-time holder of a journey-level or specialty plumber's certificate of competency, a separate credential earned through its own application and experience requirements. A general remodeling registration alone does not authorize anyone to do the plumbing.[3]
California: general building, residential remodeling, or a single trade
In California, CSLB licensing kicks in for any job that pulls a building permit, adds an employee to the crew, or reaches 1,000 dollars combined for labor and materials. A general building license, the B classification, covers projects that call for more than two unrelated trades, which fits most full bathroom remodels.[4]
CSLB also issues a residential remodeling classification for work on existing homes, meant for a single contract that combines at least three unrelated trades. That license can only make minor changes to the plumbing, electrical or mechanical systems tied to installing or swapping fixtures. Moving supply and drain lines, or any larger plumbing system work, calls for a licensed plumbing contractor instead.[5]
Large-format tile work has its own classification too, separate from both plumbing and general building.[5]
Florida: certified or registered, plus plumbing on its own
Florida requires a person to be certified or registered before they can contract in the state, on top of whatever a county or city adds locally.[6]
A building contractor's license there covers remodeling, repair or improvement work on a building of any size, as long as the work does not touch its structural members. A residential contractor's license is narrower: one-, two- or three-family homes up to two habitable stories over one uninhabitable story. Plumbing is defined as its own contractor category under the same statute, separate from building and residential work.[7]
Florida also carves out casual or minor work under 2,500 dollars total, and lets a real estate licensee handle repair or remodeling work under 5,000 dollars as the owner's agent. Past those figures, the certification and registration rules apply.[8]
Why there is no blanket handyman license
None of the three states hand out a general small-jobs exemption for bathroom work the way people sometimes assume. Washington's cutoff is 500 dollars and disappears the moment someone advertises as a contractor. California's line is 1,000 dollars in combined labor and materials, or any job needing a permit or employees. Florida's is 2,500 dollars for casual, minor work. A typical bathroom remodel, with its permit and its plumbing, clears all three thresholds without much effort.[2],[4],[8]