Form 8813 is the payment voucher a partnership sends with its quarterly section 1446 withholding tax on income effectively connected with a U.S. business that's allocable to foreign partners. Payments are due on or before the 15th day of the 4th, 6th, 9th and 12th months of the partnership's tax year.
Everything here comes from the IRS Instructions for Forms 8804, 8805, and 8813 (Rev. 1-2026) and the December 2008 Form 8813, which is still the current revision, as of October 2026.
How 8813 fits with 8804 and 8805
| Form | What it does | When |
|---|---|---|
| Form 8813 | Voucher for each installment of section 1446 tax during the year | 15th day of the 4th, 6th, 9th and 12th months |
| Form 8804 | Annual return reporting the total section 1446 tax | Generally the 15th day of the 3rd month after the year ends |
| Form 8805 | Statement for each foreign partner showing tax paid on their behalf | Filed with Form 8804 |
Every partnership other than a publicly traded partnership with effectively connected gross income allocable to a foreign partner must file Form 8804, even with no withholding tax liability. Form 8813 only comes into play when there's tax to pay during the year.
For a calendar-year partnership
| Installment | Due on or before |
|---|---|
| First | April 15 |
| Second | June 15 |
| Third | September 15 |
| Fourth | December 15 |
Those dates are simply the 15th day of the 4th, 6th, 9th and 12th months applied to a January to December year. A fiscal-year partnership counts from the first month of its own tax year.
How much each installment is
The tax equals the applicable percentage of effectively connected taxable income (ECTI) allocable to foreign partners. For all corporate partners the rate is 21%. For non-corporate foreign partners it's generally 37%, though a partnership can use a lower preferential rate on types of income, such as long-term capital gain, where it knows the partner is entitled to that rate.
Each installment is the sum of the installments for each foreign partner, worked out using the principles of section 6655 and Regulations section 1.1446-3. The IRS tool for that is Form 8804-W, Installment Payments of Section 1446 Tax for Partnerships. A foreign partner can also certify deductions and losses to the partnership to reduce the amount withheld.
Paying with the voucher
- Enter the partnership's U.S. employer identification number and the amount of the payment.
- Enter the partnership's name and address.
- Make the check or money order payable to United States Treasury.
- Write the partnership's EIN, the tax year and Form 8813 on the check or money order.
- Don't staple or attach the voucher to the payment, and don't send cash.
- If Regulations section 1.1446-6 applies, attach all required Forms 8804-C and the computations.
- Mail to Internal Revenue Service Center, P.O. Box 409101, Ogden, UT 84409.
The alternative is EFTPS, the Electronic Federal Tax Payment System. Paying through EFTPS replaces the check, but Forms 8804 and 8805 still have to be filed, and 8813 too where it applies.
The 10-day notice most partnerships forget
Each time it makes an installment payment, the partnership must tell every foreign partner their share of the tax paid. That notice is due within 10 days of the installment due date, or of the payment date if it's paid. Partners use it to adjust their own estimated tax, so a missed notice causes problems on their side as well as yours.
Every foreign partner needs a U.S. TIN
To make sure the withholding is credited to the right person, the partnership must give a U.S. taxpayer identification number for each foreign partner and tell any partner without one that they need it. For an individual that's a Social Security number or an ITIN, applied for on Form W-7 by people who can't get an SSN. For any other partner it's the U.S. employer identification number. A partnership without its own EIN applies at IRS.gov/EIN, or by phone on 267-941-1099 if its principal place of business is outside the United States.
The year-end forms that follow
Forms 8804 and 8805 are generally due by the 15th day of the 3rd month after the partnership's year ends, or the 15th day of the 6th month for partnerships that keep their books outside the United States and Puerto Rico. They're filed separately from Form 1065, and Form 7004 extends the time to file them but not the time to pay.
If payments fall behind
Interest is charged on tax not paid by the due date, even if an extension to file is granted. Filing Form 7004 doesn't extend the time to pay, so a partnership extending Form 8804 should pay the estimated balance with Form 7004 to avoid the late payment penalty. A late Form 8804 can cost 5% of the unpaid tax for each month or part of a month, up to 25%, unless there's reasonable cause.
The verdict
If your partnership has any foreign partner with effectively connected income, put the four 8813 dates in the calendar at the start of the year, work each one out on Form 8804-W, and send partners their notice within 10 days. Use EFTPS if you can: it removes the risk of a voucher and check going astray in the post.
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Frequently asked questions
What is Form 8813?
It's the Partnership Withholding Tax Payment Voucher used to pay section 1446 withholding tax on effectively connected income allocable to foreign partners.
When are Form 8813 payments due?
On or before the 15th day of the 4th, 6th, 9th and 12th months of the partnership's tax year.
What is the section 1446 withholding rate?
21% for corporate partners and generally 37% for non-corporate foreign partners.
Can I pay section 1446 tax without Form 8813?
Yes. Payments can go through EFTPS instead of a check with the voucher, but Forms 8804 and 8805 must still be filed.
Where do I mail Form 8813?
Internal Revenue Service Center, P.O. Box 409101, Ogden, UT 84409.
Are foreign partners told about Form 8813 payments?
Yes, within 10 days of the installment due date or the payment date, showing each partner's share of the tax paid.
Is Form 8813 filed with Form 1065?
No. Forms 8804, 8805 and 8813 are filed separately from Form 1065, at the Ogden service center address.
How do I work out each Form 8813 installment?
Use Form 8804-W, applying the principles of section 6655 and Regulations section 1.1446-3 to each foreign partner's share of ECTI.
Do publicly traded partnerships use Form 8813?
No. The Form 8804 filing rule applies to every partnership other than a publicly traded partnership.
