Filing your Washington sales tax return is simple with the state’s online system. You can file and pay directly through Washington’s My DOR portal, as long as your business is registered to collect and remit sales tax.
This guide walks you through the step-by-step process of filing online so you can submit returns on time, avoid penalties, and stay compliant with Washington’s sales tax rules.
What You Need Before Filing
Before filing your sales tax return, you must prepare specific records to ensure your report is accurate. Here are the standard documents and information required to file a sales tax return in Washington.
- Washington Taxpayer Account Number (Sales Tax Permit) – You’re required to provide your Washington State tax account ID or Unified Business Identifier (UBI) number to file your sales tax return. Once your registration with the Washington Department of Revenue is approved, you should receive this documentation via mail. Also, this number can be found on your Washington Sales Tax Permit document.
- My DOR Account Log-in Details – The primary way to file your Washington sales tax return online is by logging into your My DOR account. To access the site, ensure you have your log-in credentials ready (e.g., your username and password). Use your SecureAccess Washington (SAW) to log in and access My DOR.
- Total Sales – Gather your total revenue during the filing period. This includes all sales, whether they’re taxable or not. This amount is reported on your Combined Excise Tax Return for the Business & Occupation (B&O) tax. Even if you currently have no sales records, you’re still required to file a return.
- Taxable Sales – Compile the total taxable sales your business made within the filing period.
- Taxable Purchases – Verify the total amount of taxable purchases your business spent within the filing period. This applies to both in-state and out-of-state transactions and is reported on your return as “use tax,” which is due when the seller did not collect sales tax.
- Local Sales Tax Report – Washington requires businesses to file a local sales tax report as well. This means you must list all your sales in each city, county, or other local jurisdiction in Washington, using the specific location codes provided by the Department of Revenue.
- Bank Account and Routing Number – Select which bank account you want to use for paying the due taxes in your report. Prepare your bank details and routing number in advance.
- Filing Frequency Schedule – The state assigns a specific due date for every registered business. This is based on your estimated tax liability. To determine your designated schedule, refer to your Washington Sales Tax Permit document.
Step-by-Step: How to File Washington Sales Tax Online
Step 1. Go to the Washington State Department of Revenue – My DOR website. Step 2. Enter your Account Credentials: Log in using your username and password. Check your shared email/phone number and enter the OTP when applicable.
Step 3. Prepare your Ecommerce Sales Tax Data (e.g., Taxes Report from Shopify).
Step 4. Under File and Pay, click File and Pay Your Return.
Step 5. Enter the Gross Sales amount accurately, then click Next.
Step 6. Enter the applicable City/County Sales Tax information, then click Next.
Step 7. Review the Total Tax Due and make sure it matches the amount shown in the Tax Report. Once confirmed, click Next.
Step 8. Enter the client’s bank details and set the payment date according to the return’s due date. After verifying the information, click Next.
Step 9. Enter the login password to authorize the filing, then click Submit.
Step 10. Save the confirmation in your preferred location for recordkeeping purposes. Keeping online records using Google Drive is a common option.
Helpful tip: If the filing process is interrupted by internet issues, website downtime, or other disruptions. You can always click on “Save and Submit Later” to avoid losing your progress.
Due Dates
The filing frequency and due dates with which a business must file and remit sales tax in Washington are determined by the DOR.
For monthly filers, returns are due on the 25th of the month following the reporting period. For quarterly filers, returns are due on the last day of the month following the tax quarter (e.g., Q1 is due April 30). For annual filers, the return is due on April 15th of the following year. If the due date falls on a weekend or a legal holiday, the deadline is extended to the next business day. A business must be aware of its specific filing frequency and due dates to avoid penalties.| FREQUENCY | REQUIREMENT | REPORTING PERIOD | DUE DATE |
| Monthly | Annual tax liability of $4,801 or greater | Monthly | 25th day of the month following the reporting period |
| Quarterly | Annual tax liability between $1,051 – $4,800 |
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| Annually | Annual tax liability of $1,050 or less | January 1 to December 31 | April 15 |
Timely Filing Discount
Some states offer businesses a discount for the timely collection, filing, and remittance of sales tax. Currently, Washington does not offer a timely filing discount. While no discount is available simply for timely remittance, other types of deductions can reduce a business’s taxable gross sales. For example, cash and trade discounts given to customers for early payment can be deducted from the gross proceeds of a sale, provided that the amount was previously reported.Filing Amended Returns
If a business discovers an error on a previously filed return, it must file an amended return to correct the mistake. This is particularly important for returns that were initially filed with “no business activity” when, in fact, there was taxable business. In Washington, businesses can amend tax returns electronically through My DOR or by paper. The Washington State Department of Revenue requires all taxpayers to file and pay their excise taxes electronically unless they have received a waiver from the department. Also, electronic filing lets you update returns, submit schedules for multiple periods, and make payments online. Suppose you have been granted a waiver and are filing by paper. In that case, you must copy the original return, mark it as amended, draw a single line through any incorrect information, write the correct figures in black ink, and attach a short letter explaining the changes. Always include payment for additional taxes owed, and mail everything to: Washington State Department of Revenue Taxpayer Account Administration PO Box 47476 Olympia, WA 98504-7476 Refunds are limited to four years, and penalties will apply for late or underreported taxes, especially if you amend a return that was previously filed with “no business” to now report business activity.Refunds
Registered Washington businesses may request a refund directly from the Department of Revenue if they believe they have overpaid taxes, penalties, or interest. Businesses must file a refund claim within four years from the end of the calendar year in which they originally paid the taxes. To initiate a refund claim, a business must submit a written request or the official “Application for Refund or Credit” form to the Department of Revenue. You must also submit supporting documentation to substantiate the overpayment. If the Department requests additional documents, you must submit them within 90 days of the initial notification. If a refund request is denied, a business has the right to an administrative review. This requires filing a written petition with the Administrative Review & Hearings Division within 30 days of the denial. You can submit refund claims electronically through your My DOR account or mail them to: Washington State Department of Revenue Attn: Refunds PO Box 47476 Olympia, WA 98504-7476Filing Zero Returns in Washington
Even if a business has no taxable sales or other business activities during a given reporting period, it is still mandatory to file a return by the due date. This “no business” or zero return is necessary to maintain an active account status and avoid penalties for non-filing. However, some businesses may qualify for an “Active Non-reporting” status from the Washington State Department of Revenue (DOR). If the Department grants a business this status, the business does not need to file returns. Businesses that do not have an “Active Non-reporting” status must file a zero return. You can file a no business activity return electronically through your My DOR account, using the Express File option on the DOR website, or by phone. The Washington DOR provides three convenient electronic methods for filing a zero return:- Express File: This is the quickest option, available at dor.wa.gov/expressfilenobiz. It does not require a My DOR login. A filer enters their Account ID number, confirms there was no activity, and provides their contact information to submit the return.
- E-file in My DOR: For businesses with an active My DOR account, a filer can log in, select the File Return link, and then choose the Report No Business option. The system will generate a return totaling $0.00 for the filer to review and submit.
- File by Phone: The DOR also offers a 24/7 automated phone system at 360-705-6705. A filer can report no business activity by entering specific prompts and their nine-digit Account ID number.
Other Filing Methods in Washington
If you’re having difficulties filing your Washington sales tax return online, you can try other options.- File with TaxHero – Let expert accountants in TaxHero prepare your sales tax returns for you. We’ll take everything off your hands so that you can spend your time more efficiently managing your business.