Washington Estate Tax Forms & Deadlines
Last updated: 24 Oct 2025 • Author: Alexander Foelsche CPA (US), WP (DE), RE (CH)
Washington Estate Tax — Forms & Deadlines
One-stop page for Washington’s state Estate & Transfer Tax: who must file, which forms you need, due dates and extensions (via My DOR), payment & interest, the applicable exclusion amount, and practical checklists. Get help filing in Washington
Who must file?
Core forms & where to get them
Washington forms (Department of Revenue)
- Washington State Estate & Transfer Tax Return (fillable PDF).
- Excel auto-fill version of the return (optional).
- Application for Extension of Time to File (use My DOR for fastest service).
- Return Upload Template & instructions (for submitting through My DOR).
See the current Estate Tax Filing Instructions (REV 85-0050) for line-by-line guidance.
Federal attachments (typical)
- Form 706 (or 706-NA) pages/schedules and Forms 712 (life insurance).
- Appraisals, deeds/titles for WA real/tangible property; will/trust; letters of authority.
- Proof of payment for administration expenses and other claimed deductions.
If no federal return is required, include consistent pro-forma schedules to support WA values and deductions.
Deadlines, extensions & interest
| Item | When due | Where | Notes |
|---|---|---|---|
| Estate & Transfer Tax Return | 9 months after date of death | Submit via My DOR (preferred) or by mail per instructions | Attach federal schedules/appraisals. Keep copies of all receipts and confirmations. Estimate tax with the calculator |
| Extension to file | Request by the original due date | My DOR or Extension Application | Typically grants up to 6 months to file; does not extend time to pay. WA estate tax return instructions |
| Payment of tax | By the 9-month due date | My DOR (e-pay) or check with cover letter | Interest accrues after the due date. 2025 statutory interest rate: 7%. Penalties may apply for late filing/payment. |
| QFOBI deduction | With return | Return schedules | Maximum deduction: $3,000,000 for deaths 7/1/2025–12/31/2025 (previously $2,500,000). Keep eligibility documentation. |
Applicable exclusion amount (by date of death)
| Date of death | Filing threshold | Applicable exclusion amount | Notes |
|---|---|---|---|
| Through 6/30/2025 | $2,193,000 | $2,193,000 | Unchanged from prior years. |
| 7/1/2025–12/31/2025 | $3,000,000 | $3,000,000 | DOR updated table effective July 1, 2025. |
| 2026 | To be published | To be published | DOR indicates amounts will be calculated and posted in December 2025. |
How to file & pay
File electronically
- Use My DOR to upload the return (PDF/Excel) with the DOR Upload Template.
- Track submission confirmations; print/save for probate records.
Paper filing by mail is permitted per instructions, but electronic filing speeds processing.
Pay electronically
- Make e-payments through My DOR (ACH/e-check, where available).
- If paying by check, follow the remittance address and cover-sheet instructions in the current packet.
- Consider a tentative payment by month 9 if appraisals are pending to limit interest.
Practical checklists
Before filing
- Confirm residency and list WA-situs real/tangible assets (for nonresidents).
- Collect federal schedules (706/706-NA), appraisals, and titling documents.
- Model the exclusion for the applicable date of death and any QFOBI deduction.
- Plan liquidity to pay by month 9 (even if you’ll extend to file).
When extending
- Submit the Extension Application via My DOR by the original due date.
- Make an estimated payment by month 9 to reduce interest.
- Track all payments/receipts for reporting on the return.
FAQs
When is the Washington estate tax return due?
Nine months after the date of death. You can request an extension to file via My DOR, but this does not extend time to pay.
What is the exclusion amount?
For deaths through 6/30/2025: $2,193,000. For deaths 7/1/2025–12/31/2025: $3,000,000. DOR will publish 2026 amounts in December 2025.
How do I request an extension?
Apply through My DOR (fastest) or file the state Application for Extension of Time to File by the original due date.
What is the interest rate on late payments?
DOR publishes annual rates. For 2025 the interest rate is 7%. Interest accrues after the original due date until paid.
Is there a special deduction for family businesses?
Yes. The Qualified Family-Owned Business Interests (QFOBI) deduction can reduce the Washington base (max $3,000,000 for deaths 7/1/2025–12/31/2025), subject to strict eligibility and documentation.
References
- Washington DOR — Estate tax tables (exclusion amounts, interest rates, QFOBI limits).
- Washington DOR — Estate tax filing options & forms (Return, Excel version, Extension, Upload Template).
- Washington DOR — Estate & Transfer Tax overview and My DOR extension guidance.
- REV 85-0050 — Estate Tax Filing Instructions (current version).
- WAC 458-57 (estate tax rules), RCW 83 (estate & transfer tax statutes).