Extension: If the project will not be completed by the original expiration date shown on your certificate, you may request an extended expiration date by mailing or faxing a request to the Department.
Project Cost Increase: If the project's estimated costs will be exceeded, you may request an amended certificate stating a revised amount upon which the deferral taxes are requested. Requests must be mailed or faxed to the Department.
Return a copy of the certificate to:
Department of Revenue
PO Box 447477
Olympia, WA 98507-7477
or fax to (360) 586-2163