A $40 returned item fee will be assessed on all payment types returned by the bank to the Treasurer’s Office for any reason. Payments will be voided for each parcel’s taxes paid by that payment type. Taxes are then subject to delinquent charges.



Certified funds (bank certified, cashier’s checks and cash) are required for payment on all delinquent accounts subject to personal property distraint or property tax foreclosure.



Taxes are due on April 30th each year. Taxes $50 or more can be paid in two installments, half being due on or before April 30th and the second half due on or before October 31st of each year. There is NO grace period. The postmark (US Post Office Cancellation) is the determining payment date for all mailed payments (RCW 1.12.070). To comply with state statute, all payments are reviewed by postmark date to determine if they are on time. NOTE: The date written on your check will not be considered the payment date. If you drop your payment into any mail receptacle, you must make certain the US Postal Service postmark will be appropriate for the legal payment date. We are not responsible for US Postal Service postmarks. This is between the taxpayer and the US Postal Service. Please check with your local US Postal Service office for pick up and mail delivery cut off times. We suggest mailing early three (3) to (5) days early.

If a due date falls on a Saturday or Sunday, the next Monday is the acceptable due date for payments to be considered on time.



Interest & Penalty on Delinquent Taxes per Engrossed Substitute House Bill 1401 Amending RCW 84.56.020 – Interest of 1% per month on full amount due (from month of delinquency to month of payment). Penalty on all property taxes are temporarily eliminated for 2022. Penalties assessed prior to January 1, 2022 remain due and payable.

Administrative collection costs are added during the personal property distraint and real property collection and foreclosure process.

Business Personal property is subject to distraint proceedings as soon as it becomes delinquent in the year it is billed.

Personal Mobile Homes are subject to distraint proceedings three years from the tax due date.

Real Property is subject to foreclosure proceedings three years from the tax due date.



Real Property taxes – assessed on land and improvements – (Please note that improvements can include any well, septic, driveway, home, out buildings and mobile homes not assessed as personal property).

Personal Property taxes – include mobile homes not assessed as real property, boat houses, farm equipment, business equipment and leased equipment.



Have your tax payment automatically deducted from your US bank checking or savings account on its due date April 30th and October 31st. Click here for more information.



Visit our credit/debit card payment information section.



Return your tax statement(s) and check made payable to the MASON COUNTY TREASURER, in the envelope provided to you, or using your own envelope, mail to:

Mason County Treasurer's Office
PO Box 429
Shelton, WA 98584-0429

If you wish a receipt, please enclosed a written request and a postage paid return envelope with your property tax payment. Otherwise, your check is your receipt.



Office hours are 9:00 a.m. to 4:00 p.m., Monday through Friday, with the exception of legal holidays. We are located on the 2nd floor of Mason County Building 1, 411 N 5th St, Shelton, Washington.

A drive-up payment drop box is located in the alley adjacent to Mason County Building 1.