ContractorHistory

Plumbing contractors in Washington

2,262 active plumbing contractors are registered with Washington L&I. 4,448 registrations are on record in all, including expired and other statuses.

199 of the active plumbing contractors registered in Washington are based in other states.

By the numbers

Active registrations
2,262
Registrations on record, all statuses
4,448
Registered in the last 12 months
310
Median years registered, active
3
Suspension on record
330
Complaint records matched
69
Active, based outside Washington
199

Plumbing contractors by city

Active registrations in the Washington cities with the most, among cities that have a directory page.

Longest registered

  1. CULLIGANRegistered since December 1, 1993 · Kennewick, WA
  2. CLEAN WATER SPECIALISTS INCRegistered since October 23, 1998 · Pasco, WA
  3. CUSTOM WATER SOLUTIONS INCRegistered since May 14, 1999 · Chehalis, WA
  4. NORTHWEST WATER TREATMENT INCRegistered since September 12, 2001 · Lacey, WA
  5. AQUA BACKFLOW TESTINGRegistered since February 4, 2008 · Sumner, WA

Recently registered

  1. ISLAND PLBG & PIPE WORKS LLCRegistered on October 5, 2026 · Oak Harbor, WA
  2. PIPED-UP PLUMBING LLCRegistered on October 2, 2026 · Spokane, WA
  3. KENNYDALE PLUMBING LLCRegistered on October 1, 2026 · Renton, WA
  4. GRAY SERVICE PLUMBINGRegistered on September 29, 2026 · Rockford, WA
  5. C&C WIRTH MECHANICAL LLCRegistered on September 25, 2026 · Post Falls, ID

Active registrations, by the effective date on the state's record.

2,262 active registrations

Businesses by registered name and license number. Show all 4,448 registrations on record, including expired.