Three Washington Payroll Taxes Your Firm Can't Put on Autopilot

If your firm runs payroll for Seattle-area and Washington clients, your payroll platform will calculate the state's payroll premiums each pay period and file the quarterly reports. What it cannot do is make the three setup decisions those premiums turn on. When one of them is wrong, the platform keeps remitting the wrong number all quarter, and it is your firm's name on the correction. The three are Paid Family and Medical Leave (PFML), WA Cares, and workers' compensation through Labor & Industries (L&I). Automation handles the arithmetic for all three; each still needs a person to decide one thing first.

This is written for firms that offer client payroll as a service across many Washington businesses, not a ranked list of payroll software. Washington has no state income tax, so there is no state wage withholding to set up; the judgment concentrates in these three programs and in applying the right local minimum wage. Where a figure comes from a vendor rather than a state agency, we say so.

Paid Leave: automate the 1.13%, decide the employer share

Automate the premium calculation and the quarterly report; the decision a person owns is whether each client owes the employer share. For 2026 the PFML premium is 1.13% of each employee's gross wages, not including tips, up to the Social Security cap of $184,500 for the year. That is up from 0.92% in 2025, so a platform carrying last year's rate is wrong for every client. Employees pay 71.43% of the premium and employers pay 28.57%.

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The setup decision is the employer share. A business the Employment Security Department classifies as having fewer than 50 employees is not required to pay the employer portion, but it must still collect the employee premium or pay it on the employee's behalf. That headcount is counted per client for the prior calendar year, and it decides whether the 28.57% is owed at all. Tell the platform a small client is a large one and it over-remits; tell it the reverse and the client underpays. Premiums are reported quarterly, and the report is due even when a client had no payroll that quarter.

WA Cares: a flat 0.58%, until an exemption letter reaches you

Automate the 0.58% deduction and remit it on the same report as Paid Leave; the recurring human task is tracking exemptions. WA Cares is 0.58% of gross wages, and unlike Paid Leave it is not capped at the Social Security maximum, so the deduction continues on every dollar of wages all year. The premium is paid entirely by employees, though an employer may elect to cover some or all of it. Since the third quarter of 2023, employers report WA Cares and Paid Leave together on the same quarterly Employment Security report.

Exemptions are where automation needs a person in the loop. An employee applies to the state for an exemption and, if approved, gives the employer a copy of the approval letter. From then on the employer keeps that letter on file and stops deducting WA Cares. Premiums already withheld before the employee provided the letter are not refunded. A payroll system has no way to know an exemption exists until someone records it, so the firm needs a per-client exemption log and a step that stops the deduction the moment a letter is received.

Workers' comp: the one premium that isn't a percent of pay

L&I is billed by the hour, not as a percentage of wages, so automation needs accurate hours by risk class and the firm has to assign the class and set the employee-deduction choice. Employers buy workers' compensation coverage through L&I's state fund (or self-insure). The premium is the hours an employee works multiplied by an hourly rate for their risk classification; L&I sets each classification's base rates from the previous five years of claim costs and adjusts them with an experience factor built from the business's own last three years of hours and claims.

Two setup decisions sit under that. First, the risk classification: an office bookkeeper and a warehouse worker are different classes, and putting an employee in the wrong one misstates the premium and creates audit exposure. Second, the employee deduction. Under state law a portion of the premium equal to one-half of the Medical Aid, Stay at Work, and Supplemental Pension amounts may be collected from employees by payroll deduction; the Accident Fund portion is the employer's alone, and some businesses choose to pay the whole premium themselves. The firm reports each client's hours by class to L&I quarterly, and like the Paid Leave report, it is filed even in a quarter with no hours.

One client's quarter, reconciled

Here is a labeled, illustrative example, not a result for any client, to show where the review time goes. A Seattle client has three employees and, with fewer than 50, owes no Paid Leave employer share. Take one employee with $18,000 in first-quarter gross wages. Paid Leave on that is 1.13% × $18,000 = $203.40 total; the employee pays 71.43%, or $145.29, and because the client is a small employer the $58.11 employer share is not owed, so $145.29 is collected and remitted. WA Cares, if no exemption applied, would be 0.58% × $18,000 = $104.40.

Now the catch. This employee gave the firm an approved WA Cares exemption letter on March 1, so the deduction should stop for pay dates from then on. January and February wages of $12,000 were correctly subject to the premium: 0.58% × $12,000 = $69.60. The $6,000 paid in March should not have been deducted, but the platform was never flagged and took 0.58% × $6,000 = $34.80 anyway. Reconciling the quarter means catching that $34.80, turning off the deduction, and refunding it to the employee; the $69.60 withheld before the letter arrived stays, because premiums collected before an exemption is provided are not refunded. On the L&I side, the same review confirms all three employees sit in the right risk class and that the client's chosen employee-deduction share was applied to the quarter's hours. The arithmetic is simple; the work is knowing which lines a person has to look at.

What stays the firm's job

Splitting the work this way is a recommended method, not an agency rule. Automation does the math and the filing. The firm owns the setup and the sign-off: the per-client employer-share determination for Paid Leave, the WA Cares exemption log, the L&I risk class and deduction choice, and a review of each quarterly report before it is submitted. It also owns the wage floor. Seattle's minimum wage rose to $21.30 an hour for all employers on January 1, 2026, up from $20.76, a single rate since the small-employer tier ended in 2025. A firm with clients in more than one city cannot set one wage for all of them; some nearby cities adopt their own minimum wage, so the floor follows the city where each client's staff actually work. None of this is removed by the payroll platform, and none of it is removed by Washington's lack of a state income tax. For where a client-payroll service fits among a firm's other first AI and automation projects, see where a firm should start with AI.

Sources

• Washington Employment Security Department: Paid Family & Medical Leave premium rate increases to 1.13% in 2026
• Washington Paid Leave: Employer roles and responsibilities (2026 rate, Social Security cap, combined reporting)
• WA Cares Fund: Employer information (0.58% premium, no wage cap, exemptions, combined report)
• Washington L&I: How L&I calculates premium rates
• Washington L&I: Workers' compensation overview (risk classes, four funds, employee payroll deduction)
• Seattle Office of Labor Standards: 2026 minimum wage increase memo