Internal administrative services support activities to effectively carryout agency operations and the strategic business plan. These services include: the overall management of the agency through executive oversight, internal auditing, accounting and budgeting, payroll administration, facilities management, purchasing, human resources, organizational development, and legal services provided by the Attorney General's Office.

The Department of Revenue has a statutory obligation to ensure uniformity within the state's property tax system and oversee the administration of property taxes at both the state and local levels. The Department also determines the state school levy; conducts complex appraisals on commercial, industrial, and special use properties; administers property tax exemptions and deferral programs; and provides guidance, training, and assistance on property tax issues to county officials. The Department also performs appraisals throughout the state on inter-county and inter-state utility companies. These utilities have a combined assessed value in excess of $15 billion and provide over $179 million dollars in property tax each year for local government and state schools.

The Department of Revenue is responsible for the fair, efficient, and uniform administration of state tax laws. Primary activities include taxpayer registration, tax return processing, collection activities, accounting for and distributing state and local tax revenues, promotion of voluntary compliance through taxpayer education, information and assistance, and enforcement. These activities are conducted from offices throughout the state and are supported by a statewide computer network.

Audit Division activities support the voluntary reporting and payment of taxes and the administration of the tax system. Audit Division staff are assigned to field offices across the state and other locations throughout the United States, or as roving out-of-state auditors based out of Washington. Auditors conduct audits of businesses that have activity in Washington State, working directly with taxpayers to verify the accuracy of taxes reported, and to identify and correct improper reporting, leveling the tax burden on Washington State businesses. In addition to educating taxpayers through the audit process, division activities also include educating taxpayers about tax reporting through business outreach seminars, consultation visits, and other speaking engagements. Internally, the Audit Division assists the Department in understanding the practical application of law by identifying changes in technology, business activities, and industries. Externally, the Audit Division is, in many cases, a “face” for the Department and often serves as a taxpayer's first and only personal contact with the Department.

Tax policy activities focus on providing timely and accurate information for the legislature, other agencies and Executive branch decision makers, clear and consistent guidance to taxpayers, employees, and the public regarding tax law and policy application, and coordinating interdivisional policy analysis and studies. Specific functions include: responding to legislative and constituent requests; coordinating interdepartmental policy analysis and studies; preparing fiscal analysis estimates; preparing fiscal notes; analyzing and drafting legislation to ensure legislation is administrable and provides for sound tax policy; advocating for agency request legislation; developing legislation proposals; reviewing and drafting rule revisions; providing technical advice to operating divisions; coordinating with the Attorney’s General Office in litigation matters, and forecasting non-general fund revenues.

The Department receives over 900 taxpayer requests for review and appeals each year. These matters are comprised of five case types: small claims (single issue, up to $50,000 in tax, penalties, and interest); executive (first impression, industry wide significance); maintenance (regular cases); Administrative Procedures Act Appeals, and Board of Tax Appeals (BTA) informal appeals from agency final decisions. When a case is concluded the Department issues written determinations, renders confidential tax law interpretations, negotiates settlements of tax disputes, executes settlement closing agreements when appropriate, and publishes select determinations. When these cases are appealed to the BTA, the division presents the agency case during informal proceedings. The BTA renders the final decision

The Department administers the provisions of the State Uniform Unclaimed Property Act (63.29 RCW). The unclaimed property program is a consumer protection program charged to return abandoned property to the property owner. Businesses report abandoned property to the state annually and the Department attempts to locate the owners through advertising and by providing public access to abandoned property information. The Department's role is to act in the interest of the property owners and return the abandoned property to the rightful owners whenever possible. Examples of abandoned property include utility deposits, insurance policies, safety deposit box contents, dividends, and savings accounts. Unclaimed property does not include real estate, vehicles, and most other physical property. (Unclaimed Personal Property Account-Nonappropriated)

The Business Licensing Service within the Department of Revenue provides one-stop licensing services. This service provides assistance with state and local general business registration, license renewals, filing of annual reports, change of ownership, change in business locations, registration and change of trade names, obtaining minor work permits, optional insurance coverage or hiring people to work in or around private residences.

The Working Families Tax Credit Division provides for the administration and processing of an annual remittance of credit to eligible Washington residents who file a federal tax return and submit an application to the Washington State Department of Revenue. With the exception a few unique residency requirements, eligibility for the working families tax credit is based largely on eligibility for the federal earned income tax credit, a tax credit for working individuals and families whose earnings are below an income threshold. While the income thresholds are calculated and published by the Internal Revenue Service, the credit amounts are defined in the RCW and may increase depending on the number of eligible dependents. The successful administration of this program is intended to stimulate local economic activity, advance racial equity, and promote economic stability and well-being for low-to-moderate income working individuals.