Get help using My DOR for estate tax. Online filing options.To file online, you must have a SecureAccess Washington (SAW) user ID. Paper filing options. You must provide proof of residence and your age with your application. Review answers to frequently asked questions below. If you don't find an answer to your question, please contact Clark County Assessor's Office. The treasurer settles with township and city treasurers for taxes collected for the county and state. Property Tax Payments for 2023 are due October 15. Information regarding your property, as well as property taxes, can be found at the Clark County Property Information Center. You may be eligible if you have limited income and you're at least 61 years old in the year you apply for the exemption.