Washington State Mileage Reimbursement Rate 2026: Laws, IRS Rate & Employer Rules

If employees use their personal vehicles for work in Washington State, there is no single statewide mileage reimbursement rate that private employers are required to use.

Many employers use the IRS standard mileage rate as a benchmark. In 2026, that rate changed mid-year. 

The optional business standard mileage rate is 72.5 cents per mile for January 1 through June 30 and 76 cents per mile beginning July 1. The IRS says the mid-year adjustment resulted from recent increases in fuel prices.

Washington employers also need to pay attention to local rules. 

Seattle's Wage Theft Ordinance treats reimbursements for employer expenses as part of compensation owed to employees, and city guidance says reimbursable expenses include costs reasonably necessary to perform the job or costs that foreseeably arise from an employer's instructions.

Here is what employers and employees should know about Washington mileage reimbursement rules, IRS rates, tax treatment, and reimbursement options in 2026.

What Is the Mileage Reimbursement Rate in Washington for 2026?

Washington does not establish a standard mileage reimbursement rate that every private employer must pay.

The Washington State Department of Labor & Industries states that reimbursements for fuel, parking fees, tolls, and other purchases employees make for the business are generally benefits provided at the employer's discretion.

Employers that reimburse mileage often use the IRS rate as a benchmark. For 2026, the IRS business mileage rates are:

• January 1 through June 30, 2026: 72.5 cents per business mile
• July 1 through December 31, 2026: 76 cents per business mile

The IRS describes these as optional standard mileage rates. 

Employers may use another reimbursement method when appropriate, provided the arrangement follows applicable tax, employment, contractual, and local requirements.

Do Employers Have to Reimburse Mileage in Washington State?

For most private employers, Washington State does not generally require reimbursement for fuel, parking, tolls, or similar business expenses.

Washington L&I says reimbursements for fuel, parking fees, tolls, and other purchases employees make for the business are generally provided at the employer's discretion under state law.

Its guidance also notes that a specific agreement or collective bargaining agreement can create additional payment obligations.

That makes a clear written policy especially useful. Employers should spell out which trips qualify, how employees document business mileage, which reimbursement method applies, and how payments are handled.

Local rules can change the analysis.

What About Mileage Reimbursement in Seattle?

Seattle has broader expense-reimbursement requirements than Washington State generally.

Under Seattle's Wage Theft Ordinance, compensation owed to employees includes reimbursements for employer expenses. 

The Seattle Office of Labor Standards explains that reimbursable expenses are those reasonably necessary to perform an employee's job duties or those that foreseeably occur because of an employer's instructions.

For an employee who is required to use a personal vehicle for work, some driving-related costs may therefore qualify as reimbursable employer expenses depending on the circumstances.

Seattle's guidance also makes clear that reimbursement depends on the particular expense and situation. 

Employers with employees performing work within Seattle city limits should review the local requirements directly rather than applying the statewide rule alone.

When Can Mileage Reimbursement Be Tax-Free?

Mileage reimbursement can generally be excluded from an employee's federal taxable wages when the reimbursement arrangement satisfies IRS accountable-plan rules.

According to IRS Publication 463, Travel, Gift, and Car Expenses, an accountable plan requires that:

1. The expense must have a business connection.
2. The employee must adequately account for the expense within a reasonable period.
3. The employee must return any excess reimbursement or allowance within a reasonable period.

When those requirements are met, reimbursements generally are not reported as employee pay. 

IRS Publication 15 also states that amounts paid under an accountable plan are not wages and are not subject to federal income, Social Security, Medicare, or FUTA taxes.

The reimbursement rate alone does not determine whether a payment is tax-free. Documentation and program structure matter too.

For mileage, employees should maintain records that substantiate business use, including the date, destination, mileage, and business purpose of each trip.

What Mileage Counts as Business Mileage in Washington?

Business mileage generally means driving for a legitimate business purpose rather than ordinary commuting between home and a regular workplace.

Examples can include driving from an office to a customer location, traveling between job sites during the workday, making deliveries or service calls, and traveling to qualifying temporary work locations.

IRS Publication 463 generally treats travel between home and a regular workplace as commuting. 

It also contains special rules for some temporary work locations and qualifying home offices, so the starting point of a trip alone does not always determine whether the mileage is business-related.

Accurate mileage records help employers separate business and personal driving while supporting reimbursement calculations and tax substantiation.

What Is the Washington State Employee Mileage Rate?

Washington state employees operate under a separate reimbursement framework.

Under RCW 43.03.060, the Washington Office of Financial Management sets the mileage allowance for eligible state officials and employees who use privately owned vehicles for official business. 

The statute requires the reimbursement method to be based on what is most advantageous or economical to the state.

Beginning January 1, 2026, OFM increased the privately owned vehicle mileage rate from 70 cents to 72.5 cents per mile.

As of July 1, 2026, the current Washington state privately owned vehicle mileage reimbursement rate is 76 cents per mile.

Those rates apply to eligible state travel. They do not establish a mandatory reimbursement rate for private-sector employers.

What Mileage Reimbursement Options Can Washington Employers Use?

Employers can choose from several approaches for reimbursing employees who use personal vehicles for work.

Cents-Per-Mile (CPM)

Cents-Per-Mile (CPM) reimburses employees for business-required vehicle costs using a set rate for each qualifying business mile.

An employer may use the IRS standard mileage rate or another CPM rate appropriate to its reimbursement program. 

If an allowance exceeds the applicable federal rate, the excess can have different tax treatment under IRS accountable-plan rules.

CPM is relatively straightforward because reimbursement is directly tied to documented business mileage.

Fixed and Variable Rate (FAVR)

Fixed and Variable Rate (FAVR) reimburses drivers for the real, business-required fixed and variable costs associated with owning and operating a personal vehicle for work.

Fixed costs can include depreciation, insurance, registration, and similar ownership expenses. Variable costs can include fuel, maintenance, and tires.

The IRS recognizes FAVR as a mileage allowance methodology and establishes specific requirements for qualifying plans.

Because the fixed and variable portions are calculated separately, a FAVR program can account for business mileage and location-specific vehicle costs instead of applying one national rate to every employee.

Tax-Free Car Allowance (TFCA)

A Tax-Free Car Allowance (TFCA) is an accountable reimbursement arrangement that can reimburse employees for the real, business-required cost of using a personal vehicle for work.

To remain tax-free, the arrangement must satisfy the applicable IRS accountable-plan requirements, including substantiation and treatment of excess payments.

For companies with different driver groups, a mixed reimbursement program may also make sense. 

An organization might use FAVR for employees with substantial recurring business mileage and CPM for employees who drive less frequently.

How Should Washington Employers Manage Mileage Reimbursement?

Start with a clear mileage reimbursement policy.

Employees should know what counts as business mileage, how mileage should be documented, what reimbursement method applies, and when reimbursements will be paid.

Employers with employees working in Seattle should also make sure their policies account for the city's requirements around necessary employer expenses.

Accurate mileage records are equally important. IRS accountable-plan rules require adequate substantiation, while reliable mileage data gives employers better visibility into how much business driving employees actually perform.

Programs should also be reviewed periodically. Fuel costs, insurance, employee driving patterns, tax rules, and local requirements can change. 

The IRS's mid-year mileage-rate adjustment in 2026 is a good example of why mileage reimbursement policies benefit from regular review.

Build a Mileage Reimbursement Program That Fits Your Washington Drivers

Washington gives most private employers flexibility in how they structure mileage reimbursement, while local rules such as Seattle's create additional considerations for some workforces.

The right approach depends on where employees work, how much they drive, and the business-required costs associated with using their personal vehicles.

Cardata helps companies design and manage mileage reimbursement programs for employees who use personal vehicles for work. 

Depending on the workforce, that can include FAVR, CPM, TFCA, or a mix of reimbursement methods for different driver groups.

From mileage capture and reimbursement calculations to compliance support and direct-to-driver payments, Cardata helps make mileage reimbursement simple for employees and easy for Finance, HR, and Operations teams to manage.