You can mail your payments to:

P.O Box 35172
Seattle, WA 98124-5172

Sumner:
Overnight mail to:
1016 57th St. E., Suite 100
Sumner, WA 98390

Reno:
Overnight mail to:
6121 Lakeside Drive Suite 150
Reno, NV 89511

Spokane:
Overnight mail to:
12423 E. Broadway Ave
Spokane, Valley, WA 99216