The short version
Swapping a toilet, sink or tub for a new one in the same spot is usually a cosmetic change and does not call for a permit. Moving or adding to the supply and drain lines does. The scope of the work, not its price tag, is what usually decides the answer.[1]
A remodel that only touches finishes, like new tile, a fresh vanity top, or a repainted room, typically clears without a trip to the permit counter at all.[1]
Plumbing
Changes to the water and drain lines are the trigger on the plumbing side of a remodel. Taking out, moving, or installing new supply or drain lines needs a permit even when the rest of the job is cosmetic.[1]
That covers running a new line for a second sink, relocating a shower to the opposite wall, or swapping in a tub whose drain lands in a different spot than the old one.[1]
Swapping a fixture for a like-for-like replacement in the same location is the exception most jurisdictions do not require a permit for.[1]
Electrical
Major electrical work needs a permit too. Installing new outlets, relocating a fixture, adding a ceiling or exhaust fan, or wiring a new circuit all fall on the permit side of the line.[1]
A bathroom exhaust fan tied into its own switch loop, or a heated-floor mat wired to a new circuit, both land in that same permitted category.[1]
Changing out a light fixture or replacing a switch in place usually does not.[1]
Structure and layout
Moving a wall or changing a bathroom's footprint is a bigger step than swapping fixtures. Florida's contracting law treats it differently too: a building contractor's license there stops covering work the moment it affects a structural member, which is exactly the point where a more specific license needs to be involved.[2]
Widening a doorway or folding a closet into the bathroom both touch framing, which is the same category of work as moving a wall.
Cosmetic work that usually skips the permit office
A new vanity in the old footprint, a new mirror, a light fixture reusing the existing electrical box, fresh paint, and new flooring that does not touch the subfloor's framing are the kinds of jobs that typically move ahead without a permit.[1]
The common thread is that nothing behind the wall changes. The moment a job opens up the wall to move a pipe or a wire, it usually falls back into permit territory even if everything else about it stayed cosmetic.[1]
Why the license rules follow the permit
Once a job needs a permit, the contractor pulling it has to be properly registered or licensed in the state where the work is happening, whether that is Washington's registration, California's CSLB license, or Florida's certification or registration.[3],[4],[5]
That is also the moment a homeowner can look the license up before signing anything, which our contractor-license guide above covers state by state.
Permits and your timeline
A permitted job adds a rough-in inspection before the walls close up and a final inspection once everything is installed, both of which can add a few days of waiting into the schedule.[6]
Our timeline guide below walks through where those inspections land in a typical bathroom remodel.