In this article
- Quick facts: Filing for sales tax in Washington
- When to file and pay Washington sales tax
- Washington sales tax filing deadlines
- How to prepare your Washington sales tax return
- How to complete and file a Washington sales tax return
- How to pay sales tax in Washington
- What happens after filing and paying Washington sales tax
- Late filing penalties and interest
- Getting third-party help with sales tax filing
- Sales tax filing in other states
If you are registered for Washington sales tax, you must file returns and pay any tax due according to the filing frequency assigned by the Washington Department of Revenue. This guide covers the filing and payment process for remote sellers and out-of-state businesses using the My DOR portal. Note that Washington's due date is the 25th of the following month, and Washington is one of the few states that also imposes a Business and Occupation (B&O) tax on sellers.
For broader information about Washington sales tax rules, rates, and exemptions, see the Washington Sales Tax Guide. For details on how to register for a Washington sales tax permit, see the Washington Sales Tax Registration Guide.
Quick facts: Filing for sales tax in Washington
Key information about filing Washington sales tax returns, including filing frequency, deadlines, and payment options.
| Fact | Detail |
|---|---|
| Filing frequency | Monthly, quarterly, or annually |
| Filing deadline | The 25th day after the period ends |
| Filing portal | My DOR |
| State sales tax rate | 6.5% (plus local taxes) |
| Economic nexus threshold | $100,000 in annual sales |
| Zero returns required | Yes |
| B&O tax | Yes, filed on the same return through My DOR |
When to file and pay Washington sales tax
The Washington Department of Revenue will assign you a filing frequency (monthly, quarterly, or annually) after you register your business. Your frequency is based on your expected or actual sales volume, with higher-volume sellers typically assigned a monthly schedule.
Washington sales tax returns and payments are due at the same time, by the 25th of the month following the end of the filing period. If the 25th falls on a weekend or holiday, the due date shifts to the next business day.
Washington sales tax filing deadlines
Washington monthly filing due dates
Reports are due on the 25th of the month following the reporting month. For example, the August sales tax report is due September 25.
| Month | Filing Deadline |
|---|---|
| January | February 25 |
| February | March 25 |
| March | April 25 |
| April | May 25 |
| May | June 25 |
| June | July 25 |
| July | August 25 |
| August | September 25 |
| September | October 25 |
| October | November 25 |
| November | December 25 |
| December | January 25 |
Washington quarterly filing due dates
| Quarter | Filing Deadline |
|---|---|
| Q1 (January 1, March 31) | April 25 |
| Q2 (April 1, June 30) | July 25 |
| Q3 (July 1, September 30) | October 25 |
| Q4 (October 1, December 31) | January 25 |
Washington annual filing due date
Reports for the previous calendar year are due on January 25.
Important note: Zero returns
Once you are registered for Washington sales tax, you must file a return for every assigned period, even when you had no taxable sales and no tax to remit. Filing a zero return through My DOR is required. Skipping a filing period can result in penalties and interest even when no tax was owed.
How to prepare your Washington sales tax return
Before working on your sales tax return, collect all sales information for the tax period. The My DOR system will guide you through each field, but you will need the following data ready.
Sales transactions
You need to know your total gross sales to Washington buyers and your taxable sales. Washington taxes digital goods and SaaS, so remote sellers providing software subscriptions or digital products must include those amounts. Sales to buyers who have provided a valid resale certificate or exemption certificate may be excluded from taxable sales.
Key reporting figures
In addition to your gross Washington sales, filing a return requires:
- Total sales and income
- Taxable sales by type (retail, digital goods, SaaS, etc.)
- Non-taxable sales and exemptions
- Deductions and adjustments
- Total sales tax collected from customers during the filing period
- Business and Occupation (B&O) tax amounts by classification (most remote sellers use the "Service and Other Activities" or "Retailing" classification)
How to complete and file a Washington sales tax return
Washington sales tax returns are filed electronically through My DOR and must be reported in US dollars.
Step-by-step: file a Washington sales tax return
1. Collect all necessary information
Gather your sales records for the tax period. Make sure you have figures for both your Retail Sales Tax (collected from customers) and your B&O tax (calculated on your gross receipts as the seller). Washington reports both on the same Excise Tax Return.
2. Log in and file online
- Log in to My DOR using your Secure Access Washington (SAW) account.
- Navigate to your Excise Tax account.
- Click the "File Return" link for the relevant filing period.
- Enter your gross sales, taxable sales, exemptions, B&O tax amounts, and total tax collected.
- Review all figures and submit your return.
3. Receive confirmation
After submitting, you will receive a confirmation number. Save this as your record of filing.
How to pay sales tax in Washington
Payment is made directly through My DOR at the time of filing. Tax payments must be in US dollars. Accepted payment methods include:
- ACH Debit: You authorize the Department's bank to withdraw the amount you owe from your bank account on the date you select.
- ACH Credit: You authorize your bank to send funds to the Department's account. You must initiate this payment each time you file.
- E-check: Enter your bank account number and routing number to make a one-time payment. This option is free of charge.
- Credit card: Visa, MasterCard, American Express, and Discover are accepted. A 2.5% processing fee is charged by a third-party vendor for this service.
What happens after filing and paying Washington sales tax
After filing and paying, keep a copy of your return and payment confirmation for your records.
- Save your filing confirmation number and payment receipt
- Keep records supporting the reported amounts (sales logs, invoices, exemption certificates)
- Continue filing according to your assigned frequency, remembering Washington's 25th due date
- File a zero return for any period with no taxable sales
➡ Need help understanding Washington sales tax rules, rates, and nexus? See the Washington Sales Tax Guide
➡ Need to register for Washington sales tax? See the Washington Sales Tax Registration Guide
Late filing penalties and interest
If you miss a Washington sales tax filing deadline, file your return as soon as possible. Failure to file returns and remit collected tax on time results in penalties and interest charges that increase the longer you wait.
Washington does not offer a timely filing discount for sales tax filers. For current penalty rates and interest charges, refer to the Washington Department of Revenue website.
Getting third-party help with sales tax filing
Quaderno can simplify your Washington sales tax compliance by generating detailed tax reports and handling the filing process on your behalf. Connect your sales data and Quaderno manages the submission to the Washington Department of Revenue, ensuring timely and accurate filing for both your Retail Sales Tax and B&O tax obligations.
Sales tax filing in other states
- Arizona Sales Tax Filing Guide
- California Sales Tax Filing Guide
- Florida Sales Tax Filing Guide
- Georgia Sales Tax Filing Guide
- Illinois Sales Tax Filing Guide
- Kentucky Sales Tax Filing Guide
- Massachusetts Sales Tax Filing Guide
- New Jersey Sales Tax Filing Guide
- New York Sales Tax Filing Guide
- Ohio Sales Tax Filing Guide
- Pennsylvania Sales Tax Filing Guide
- Rhode Island Sales Tax Filing Guide
- South Carolina Sales Tax Filing Guide
- Texas Sales Tax Filing Guide
- Virginia Sales Tax Filing Guide
Need help filing across multiple states?
Watch our webinar: US Sales Tax Registration & Filing Tips + AMA. Learn how international sellers register, file, and manage US sales tax compliance across multiple jurisdictions.
Note: At Quaderno we love providing helpful information and best practices about taxes, but we are not certified tax advisors. For further help, or if you are ever in doubt, please consult a professional tax advisor or the tax authorities.
