Washington Use Tax for Business Purchases: What Companies Need to Track

Washington use tax is designed to complement retail sales tax. When a business uses taxable property—or certain taxable services—in Washington and the appropriate sales tax was not paid at the time of purchase, the buyer can have a direct Washington tax obligation.

For most companies, use tax is not difficult because of the rate calculation. It is difficult because the transaction can enter the accounting system as an ordinary vendor bill, expense reimbursement, fixed asset, inventory adjustment or purchase from an out-of-state supplier with no visible Washington tax flag.

The best control is therefore not a year-end estimate. It is a purchasing and accounts-payable process that identifies untaxed taxable purchases close to the time they occur.

What is Washington use tax?

Washington DOR describes use tax as a tax on the use of goods or certain services in Washington when sales tax was not paid at the time of purchase. Businesses and individuals can both owe it.

For tangible personal property, liability generally arises when the property is first put to taxable use in Washington. DOR's examples include installation, storage, withdrawal from storage, distribution or another act preparatory to actual use or consumption in the state.

That framework makes use tax especially relevant to businesses that buy across state lines, move equipment into Washington, purchase from vendors that do not collect Washington tax, or withdraw items from tax-free inventory for internal use.

Which business purchases commonly create Washington use-tax exposure?

The following patterns deserve recurring review.

Common business examples include computers, office furniture, tools, machinery, equipment, supplies and taxable repair or improvement services. Industry-specific exemptions can change the result, so the fact that a purchase is “for business” is not itself an exemption.

The control question is not “Did the vendor charge tax?” It is “Was this a taxable purchase, and if so, was the correct Washington tax paid?”

How is Washington use tax calculated?

DOR states that the use-tax rate is the same combined rate that would apply to a retail sale at the relevant Washington location. The state portion is 6.5%, plus the applicable local use-tax rate.

For tangible personal property, the local rate is generally determined by the location where the property is first used in Washington. That can be different from the seller's location, the buyer's billing address or the place where an invoice was processed.

The taxable value is generally the purchase price when the item is bought and immediately put to use in Washington. Different valuation rules can apply when property was used outside Washington before being brought into the state or when the purchase price does not represent the item's value.

If sales or use tax was properly paid to another state, Washington may allow a credit against the Washington use tax otherwise due. The records should show the tax actually paid and the jurisdiction involved.

How do the 2025–2026 service changes affect business purchasers?

Starting October 1, 2025, Washington began taxing several service categories that many businesses historically purchased without retail sales tax, including specified advertising, information technology, custom website development, custom software, temporary staffing, investigation/security services and live presentations.

For buyers, that means a vendor invoice that looked normal before October 2025 may now require tax. But the correction mechanism is not identical in every case.

DOR's current ESSB 5814 FAQ states that the 2025 legislation does not explicitly impose use tax on every newly enumerated service. DOR instead explains that deferred sales tax may be due when retail sales tax was not paid at the time of sale. If a service transferred electronically also qualifies as a digital automated service, a separate use-tax framework can apply because digital automated services are subject to use tax.

This is why accounts payable should not automatically post every untaxed service invoice to a generic “use tax” bucket. The transaction should first be classified.

For the seller-side service changes, see Washington Sales Tax on Services: 2025–2026 Changes.

How does a registered Washington business report use tax?

DOR instructs registered businesses to report business-related use tax on their Washington excise tax return. The tax should be reported for the period in which the property is first put to taxable use in Washington.

Documentation matters because an invoice is also evidence of whether sales tax was paid. Washington requires retail sales tax to be separately stated on sales documents. DOR says that if a retail invoice does not separately list the sales tax, it will assume the tax was not paid.

If a vendor should have charged retail sales tax but did not, a buyer should first request a corrected invoice where appropriate. If that is not practical, DOR provides buyer-side reporting paths rather than advising the customer to simply add “sales tax” to the amount paid to the vendor.

For registered businesses, the file should preserve enough detail to explain:

• the vendor and invoice date;
• what was purchased;
• the purchase price or taxable value;
• sales or use tax already paid to another jurisdiction, if any;
• the Washington location of first use;
• the rate used;
• the reporting period in which the tax was included;
• any exemption, resale or other support for a nontaxable result.

What accounting controls help find use tax before an audit?

A strong process connects procurement, accounts payable, inventory, fixed assets and tax reporting. A tax-only review performed after year-end can miss the operational signals that explain why tax was not collected.

For businesses affected by the 2025 service expansion, DOR's temporary ESSB 5814 penalty-relief program is also relevant. It covers qualifying uncollected retail sales tax and unpaid use tax caused by those changes for periods from October 1, 2025 through December 31, 2026, subject to the program requirements.

What are common Washington use-tax mistakes?

• Assuming an out-of-state vendor's failure to collect tax means the purchase is exempt.
• Using a reseller permit for equipment or supplies consumed by the business.
• Ignoring property moved into Washington from another state.
• Using the billing address instead of the location of first use for the local rate.
• Failing to preserve evidence of sales tax paid to another state.
• Posting every untaxed service invoice to use tax without distinguishing deferred sales tax, digital-product rules, exemptions or resale treatment.
• Waiting until an audit to reconcile tax-free inventory withdrawals.

Use tax belongs inside the broader Washington transaction-tax process

Use tax is the buyer-side complement to a broader sales-tax system. A company that sells taxable products or services, buys from out-of-state vendors, uses reseller permits and operates in multiple Washington locations should not treat each of those questions as a separate spreadsheet.

The commercial owner for this topic is Washington Sales & Use Tax. For the accounting layer that supports transaction-level review and reconciliation, see Business Accounting.