05/29/2026
🛡️ Three quotes for the same tree job in Auburn. $400, $1,200, $3,500. What's the difference between them?
The cheapest is often a door-knocker with a borrowed chainsaw and no insurance. The middle quote is usually the truthful one. The highest might be a fully insured ISA Certified Arborist crew — or scope-padded. Reading the difference takes about five minutes of homework.
Three things every PNW homeowner should verify before signing anything for tree work in Kent, Federal Way, Tacoma, Puyallup, or Renton:
1️⃣ ISA Certified Arborist credential — held by the individual, not the company. Verify the certification number directly on the ISA public directory.
2️⃣ WA L&I contractor registration — mandatory in Washington. The state's free "Verify a Contractor" lookup shows active status, bond, workers' comp, and any open infractions.
3️⃣ A certificate of insurance (COI) naming the property as an additional insured for the work date — with at least $1M general liability for residential pruning. "We have insurance" is not insurance.
There's a fourth check for hazard pruning and risk reports — TRAQ qualification — covered in the full guide along with the ten site-visit questions that separate real arborists from chemical-mill operations.
Posted as a neutral educational resource by Pacific Arboriculture, ISA Certified Arborists serving the South Sound.
PNW homeowners' checklist for hiring a tree service: ISA Certified Arborist verification, WA L&I registration, insurance, and the right questions to ask.