Trefethen & CO LLC
Inst Equip/Stat Furn/Lab T/Lo · Seattle, WA · License #TREFECL742MP
Active
State-verifiedWhat does verified mean?
- State-verified — Checked against WA L&I records, updated daily.
- Owner-verified — The business claimed this listing and verified ownership — free. Claim this listing
- Proven on Subser — The business runs real jobs through Subser — measured performance, not reviews.
License facts
Trefethen & CO LLC is one of 12 Inst Equip/Stat Furn/Lab T/Lo contractors registered in Seattle, registered with WA L&I since 2026.
- License type
- CONSTRUCTION CONTRACTOR
- Effective date
- Jul 24, 2026
- Expiration date
- Jul 24, 2028
- UBI
- 602775224
- Business type
- Limited Liability Company
- Phone
- (206) 447-1770
- Location
- Seattle, WA 98134
Source: WA L&I contractor registration — verified Aug 12, 2026. Applies to every row above.
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Claim this free listingBond & insurance on file
| Bond firm | Amount | Effective | Expiration |
|---|---|---|---|
| Contractors Bonding & Insurance Co | $15,000 | Jul 23, 2026 | Continuous — until canceled |
| Insurance company | Amount | Agency | Effective | Expiration |
|---|---|---|---|---|
| National Fire Ins Co of Hartfo | $1,000,000 | — | Jun 30, 2026 | Jun 30, 2027 |
What the bond and insurance requirements mean for homeowners
Washington requires specialty contractors to file a $15,000 surety bond with the Department of Labor & Industries as a condition of registration ($30,000 for general contractors). This contractor's current filing shows a $15,000 bond.
The bond is a limited fund a homeowner (or subcontractor or supplier) can make a claim against, through the courts, if a registered contractor fails to meet its obligations on a job. Contractors must also keep general liability insurance on file — at least $50,000 in property damage and $200,000 in public liability coverage, or a $250,000 combined single limit — which covers damage the contractor causes, not workmanship disputes. The rows above are the bond and insurance filings L&I publishes for this registration; whether a specific filing applies to a specific project depends on its dates and terms.
Principals
| Name | Start date |
|---|---|
| Sean Bradley Trefethen | Jul 17, 2026 |
What is a Inst Equip/Stat Furn/Lab T/Lo contractor licensed to do in Washington?
A inst equip/stat furn/lab t/lo contractor in Washington is registered with the Department of Labor & Industries under the state's specialty contractor classification for this trade — the baseline consumer protection Washington requires before a contractor may advertise or perform work. A specialty registration covers work within its trade; projects spanning multiple trades are handled by a registered general contractor. The registration requires a $15,000 surety bond and general liability insurance on file with WA L&I. Washington currently lists 12 Inst Equip/Stat Furn/Lab T/Lo contractors registered in Seattle.
Other Inst Equip/Stat Furn/Lab T/Lo contractors in Seattle, WA
Ampersand Jill LLC
Inst Equip/Stat Furn/Lab T/Lo · Seattle, WA
License #AMPERJL760NO · $15,000 bond
Diversification INC
Inst Equip/Stat Furn/Lab T/Lo · Seattle, WA
License #DIVERI*999BP · $15,000 bond
Mynor's Hood Cleaning LLC
Inst Equip/Stat Furn/Lab T/Lo · Seattle, WA
License #MYNORHC768QK · $15,000 bond
Ogarrio Cruz Company LLC
Inst Equip/Stat Furn/Lab T/Lo · Seattle, WA
License #OGARRCC781QQ · $6,000 bond
Browse the directory
Built from Washington State L&I public records, updated Aug 12, 2026. No star ratings or reviews — verification only.