Prior to starting work on a project, a contractor offering to perform a contracting project is required to provide the customer (person hiring him/her/it) a Notice to Customer in two circumstances:
(1) Residential. When the project is for the repair, alteration, or construction of four (4) or fewer residential units or accessory structures and the bid or contract price exceeds $1,000.
(2) Commercial. When the project is for the repair, alteration, or construction of a commercial project and the bid or contract price is between $1,000 and $60,000. Commercial projects less than $1,000 or more than $60,000 do not require the notice.
The Notice to Customer need not be given when the contractor is working for another contractor. But failure to provide the Notice to Customer, when required, is an infraction.
Sample Notice to Customer: http://www.lni.wa.gov/Forms/pdf/625030af.pdf