Mason County, Washington property-tax payment and appeal deadlines
Tax bills, payment rules, and valuation-review windows are controlled by the local jurisdiction and the governing state framework. The reviewed record below separates published figures from items that still require confirmation with Mason County Assessor; Mason County Treasurer collects property taxes.
Rate context
ConfirmMason County rates vary by taxing district and tax-code area; no single countywide effective rate was published.
Statement mailing
Confirmofficial 2026 Treasurer materials reviewed confirm the payment schedule but do not publish a specific 2026 statement-mailing day; county materials state statements are generally mailed in February or March.
Payment deadline
PublishedApril 30, 2026 for the first half or full payment; October 31, 2026 for the second half; payments postmarked by the due date are timely.
Valuation protest
PublishedJuly 1, 2026 or within 30 calendar days after the Official Notice of Value was mailed, whichever is later; petition to the Mason County Board of Equalization.
Do not assume a grace period.
The reviewed record identifies the payment timing above but does not establish a universal penalty schedule for this page. Late charges, interest, collection costs, tax-sale procedures, and lien or foreclosure timelines can depend on state law and the local collector’s process. If the deadline is close or a balance is delinquent, contact the tax collector directly and request the current payoff amount in writing.
Treat a published payment deadline as a hard operational date and retain your receipt or confirmation number.
From assessment to collection
01Valuation and notice
Review the assessment notice as soon as it arrives. The protest window may run from the notice date rather than from the payment due date.
02Statement and account review
Match the tax statement to the parcel or account number and confirm exemptions, assessed value, taxing units, credits, and balance.
03Payment confirmation
Use the official collector channel, then save the receipt, transaction reference, and date posted. A bank submission is not always the same as a county posting date.