This bill creates a new homestead property tax exemption and a new renter's credit, adds new statutory sections, and amends several existing tax administration statutes. It establishes a new homestead exemption in chapter 84.36 RCW (Sec. 101) and a complementary provision in chapter 84.52 RCW (Sec. 102), creates a new chapter to be codified as Title 84A RCW for the renter's credit (sections 201–207), and amends RCW 84.48.010, 84.69.020, and RCW 82.03.190 to change appeal, refund, and equalization procedures. The act is effective January 1, 2027 only if a referenced constitutional amendment is validly submitted and approved by voters; if not approved, the act is void. The homestead exemption (effective for taxes levied for collection in 2028) exempts the first $500,000 of assessed value of a residence (per single-residence parcel or per separately owned residence in a multiunit where residences are owned/taxed separately or cooperatively). Beginning with taxes levied for collection in 2029, the exemption amount is increased annually by the prior calendar year's percentage growth in the state levy as determined by the department (which may round to the nearest $1,000). County assessors must multiply the exemption by the county combined indicated ratio for equalization, the exemption applies only to the total state property tax under RCW 84.52.065 and may not reduce state tax liability by more than the taxes that would otherwise be levied. The statute creates filing, renewal (no more than six consecutive years without renewal), occupancy, transfer, temporary absence, cooperative, and life-estate rules; requires departmentor county-approved forms signed under penalty of perjury; permits audits; requires assessors to deny or cancel improper claims; allows collection of state taxes erroneously exempted for up to six prior years with interest (but not penalties); and allows appeals under existing provisions. The homestead exemption is in addition to the exemptions in RCW 84.36.379–84.36.389. The renter's credit (effective January 1, 2028) creates a refund equal to the "rent constituting property taxes," defined as two percent of gross rent paid in the prior calendar year. The Department of Revenue administers the credit, requires annual claims by the last day of the calendar year for which the refund is claimed, and requires proof of gross rent and a mutually signed lease or rental agreement. The refund cannot exceed the amount that would have been exempt under section 101 if the claimant were eligible for the homestead exemption. The department may approve late claims within six months under specified conditions, may adjust gross rent when landlord-tenant arrangements are not arm's-length, may audit claims, and must assess and collect overpaid amounts with interest per RCW 82.32.050. A knowingly fraudulent claim carries an additional penalty equal to 50% of the overpaid amount and a ten-year bar from receiving the credit. Claimants may petition the department for correction (within 60 days) and then appeal to the Board of Tax Appeals; amended appeal deadlines and procedures are included. The department is authorized to adopt rules and, subject to appropriations, develop an electronic data exchange system with county officials. Extracted materials are incomplete in places: some procedural lists and examples of acceptable "good cause" are truncated, the statutory identity of "the department" is not specified in all homestead provisions in the provided facts (though the Department of Revenue is identified as the administering department for the renter's credit), and the specific constitutional provision and joint resolution number referenced in Sec. 102 are not provided in the extracted text.

If enacted and approved by voters, owners of qualifying residences would pay less state property tax beginning with taxes collected in 2028 because the first $500,000 of assessed value per residence would be exempt and that exemption would grow each year with the state levy; renters would be eligible for a refund equal to 2 percent of the prior year’s rent starting in 2028. The state levy must be adjusted so the exemption does not increase the tax rate, and the relief applies only to the state portion of property tax, not local levies. Homeowners and renters must file and annually renew claims, provide proof, and may be audited or have credits adjusted; improper homestead claims can trigger collection of up to six years of missed state taxes with interest, and fraudulent renter claims can bring a 50 percent penalty and a 10-year ban. County assessors, county treasurers, and the Department of Revenue will take on new responsibilities for forms, notices, outreach, audits, refunds, and appeals, and they are required to cooperate on electronic data exchange and may need additional funding to do so (the centralized system is subject to appropriation). Landlords and housing cooperatives may face scrutiny over rent levels or rules for passing savings to members. Key implementation details and the identity of some administrative rules are incomplete in the extracts, and the whole act only takes effect if voters approve the cited constitutional amendment.