Whatcom County, WashingtonProperty records & tax offices
Links open the listed public-office or service-provider website in a new tab. This directory does not collect payments.
Find the right property record
Use the property portal for ownership and assessed value, the collector for a bill or balance, and the map for parcel location. Have the address, owner name, or parcel number ready.
Tax bills & filing dates
These are the dates and qualifications recorded in the directory. Confirm your tax year and current deadline with the official office and your property’s notice.
- Payment deadline
- For 2026 taxes: first-half property taxes are due April 30, 2026; second-half taxes are due October 31, 2026. Tax statements are generally mailed in February unless the county publishes a more specific date.
- Assessment appeal
- For the 2026 assessment year (taxes payable in 2027), file by July 1, 2026 or within 30 calendar days after the 2026 change-of-value notice, whichever is later; for taxes payable in 2026, the published deadline was October 27, 2025.
Exemptions & appeals
View exemption application (opens in a new tab)Exemption filing
For 2026 taxes, Whatcom County's senior/disabled exemption application covers the 2025 qualifying year; applications may be filed through the county Assessor's program, and a denial appeal is due July 1 or within 30 days of the denial notice, whichever is later.
Senior relief
Washington senior/disabled property-tax exemption: owner is at least 61 by December 31 of the year before taxes are due (or disabled/qualifying disabled veteran), owns and occupies the principal residence more than six months, and Whatcom County household disposable income for the 2025 qualifying year is no more than $52,000 for 2026 taxes.
Valuation limits
Washington has no individual-parcel annual valuation cap verified for these counties. County assessors value taxable property at 100% of true and fair market value. The 2026 regular levy limit generally limits each taxing district's levy growth to 1% (101% limit factor), but that is a taxing-district revenue limit, not a cap on an individual property's assessed value or tax bill; new construction, improvements and voter-approved levies may be treated differently.
For a valuation appeal, use the appeal date in the tax and filing section above. Keep your notice, supporting evidence, and proof of submission.
More exemption & appeal guidance →