Washington Quarterly Estimated Taxes (2026)

Washington quarterly estimated taxes for the self-employed

Washington does not tax income in 2026, so a self-employed Washington taxpayer owes no state income tax and makes no state estimated payments — only the four federal 1040-ES installments. Your state line below is $0.

As a 1099 or self-employed Washington taxpayer you generally pay federal tax four times a year on Form 1040-ES: self-employment tax (Social Security + Medicare, the share an employer would otherwise cover) plus federal income tax on your profit. This page applies the verified 2026 federal engine and then adds Washington's 2026 state income tax on top.

Washington state income tax

Washington levies no state income tax in 2026, so your state estimated-tax line is $0. You still owe federal self-employment tax and federal income tax, paid through quarterly Form 1040-ES installments.

How this is calculated

1. Self-employment tax. Net profit × 92.35% gives net earnings from self-employment; then 12.4% Social Security up to the 2026 $184,500 wage base, 2.9% Medicare on all of it, and the 0.9% Additional Medicare Tax above your filing-status threshold. Half of the regular SE tax is an above-the-line deduction.
2. Federal income tax. Taxable income = net profit − ½ SE tax − retirement − QBI (20%) − 2026 standard deduction ($16,100 single, $32,200 MFJ, $24,150 HOH), run through the 2026 federal brackets (10–37%).
3. Washington state income tax. Washington has no state income tax, so this line is $0. State income tax is estimated on your net profit using Washington's 2026 brackets; your actual state taxable income may differ after state deductions and credits.
4. Total 2026 tax = SE tax + federal income tax + Washington state income tax.
5. Safe-harbor required payment (federal). To avoid a federal underpayment penalty you prepay the lesser of 90% of this year's federal tax or 100% of last year's federal tax (110% if prior-year AGI was over $150,000). Enter your prior-year total tax to use it; leave it blank and the tool uses the 90%-of-current-year figure.
6. Each quarterly payment = (required − expected withholding) ÷ 4, split evenly across the four 2026 federal installments: Apr 15, 2026 · Jun 15, 2026 · Sep 15, 2026 · Jan 15, 2027.

State estimated-tax timing. State estimated-tax schedules generally track the federal quarterly dates, but confirm the exact rules, thresholds, and payment vouchers with the Washington Department of Revenue — this tool models the federal 1040-ES schedule only and does not model Washington-specific estimated-tax rules. The "Washington tax ÷ 4" figure is a rough starting point, not a state safe-harbor calculation.

What this doesn't model: state-specific estimated-tax rules and vouchers, local city/county taxes, tax credits (child, education, EITC), itemized deductions, S-corp compensation splits, other household income, the annualized-income method for uneven earnings, or the full Section 199A limits on the QBI deduction. The SE-tax figures are exact Schedule SE math; the income-tax and state-tax figures are planning-grade.

Data as of July 2026 (tax year 2026). Federal brackets, standard deduction, safe-harbor, and due dates: IRS Form 1040-ES and Rev. Proc. 2025-32. SE-tax rates and the $184,500 Social Security wage base: SSA 2026. Washington schedule: Washington Department of Revenue / Tax Foundation 2026.