Form 8813 payments are due on the 15th day of the 4th, 6th, 9th, and 12th months of the partnership’s tax year. For a calendar-year partnership, that puts the four Form 8813 due dates at April 15, June 15, September 15, and January 15 of the following year. Each installment remits the Section 1446 tax the partnership has withheld on effectively connected taxable income allocated to its foreign partners, and each installment needs its own Form 8813 voucher.1Internal Revenue Service. About Form 8813, Partnership Withholding Tax Payment Voucher (Section 1446)
The Four Quarterly Deadlines
Section 1446 tax is paid in installments during the partnership’s tax year, with a separate Form 8813 accompanying each payment.2eCFR. 26 CFR 1.1446-3 – Time and Manner of Calculating and Paying Over the 1446 Tax The four deadlines fall on the 15th day of the 4th, 6th, 9th, and 12th months of the partnership’s tax year.3Internal Revenue Service. Reporting and Paying Tax on Partnership Withholding
For a calendar-year partnership, the schedule is:
- 1st installment: April 15
- 2nd installment: June 15
- 3rd installment: September 15
- 4th installment: January 15 of the following year
The January 15 payment is the final quarterly installment for the prior year, not a final settlement. The partnership still files an annual Form 8804 after the year closes, but that is a separate deadline from the four Form 8813 dates.
Fiscal-Year Partnerships
The formula is pegged to the partnership’s own tax year, not the calendar. Count to the 15th day of the 4th, 6th, 9th, and 12th months of whatever tax year you use. A partnership with a fiscal year that begins July 1, for example, owes its first installment on October 15, then December 15, March 15, and June 15.3Internal Revenue Service. Reporting and Paying Tax on Partnership Withholding
Weekends, Holidays, and Payment Lead Time
When any due date lands on a Saturday, Sunday, or federal holiday, the deadline shifts to the next business day.
How you pay affects when you have to act. The Electronic Federal Tax Payment System (EFTPS) is the Treasury’s free payment channel and gives immediate confirmation, but a payment has to be initiated at least one business day before the due date to post on time. Partnerships that have never used EFTPS need to enroll first, and enrollment typically takes several days, so a partnership handling its first installment should start that process well ahead of April 15. The alternative is mailing Form 8813 with a check or money order payable to “United States Treasury,” which must be postmarked by the deadline to count as timely. The check should reference the partnership’s EIN, name, address, tax year, and Form 8813.
Publicly Traded Partnerships Are on a Different Track
If you are looking at Form 8813 dates because you hold units in a publicly traded partnership, this schedule does not apply. Publicly traded partnerships withhold on actual distributions rather than on allocable ECTI, and they report on Forms 1042 and 1042-S instead of Forms 8804, 8805, and 8813.4eCFR. 26 CFR 1.1446-4 – Publicly Traded Partnerships The quarterly installment framework in this article covers non-PTP partnerships with foreign partners.
Penalties for Missing a Deadline
Two separate penalty regimes can apply when a Form 8813 payment is late, and they stack.
Failure-to-Deposit Penalty Under Section 6656
A partnership that fails to deposit Section 1446 tax by the quarterly deadline faces a tiered penalty calculated as a percentage of the underpaid amount:5Office of the Law Revision Counsel. 26 U.S. Code 6656 – Failure to Make Deposit of Taxes
- 1 to 5 days late: 2% of the underpayment
- 6 to 15 days late: 5% of the underpayment
- More than 15 days late: 10% of the underpayment
- Still unpaid 10 days after the first IRS delinquency notice: 15% of the underpayment
These penalties are charged to the partnership, not to the foreign partner whose income triggered the withholding.
Interest and the Section 6655 Addition to Tax
Interest runs on any late amount from the original due date until the date of payment. The underpayment interest rate is the federal short-term rate plus three percentage points, recalculated each quarter.6Office of the Law Revision Counsel. 26 U.S. Code 6621 – Determination of Rate of Interest
Underpaying a required installment during the year can also trigger an addition to tax under Section 6655, which functions like an interest charge running from each installment’s due date until the earlier of the annual return due date or the date the shortfall is paid.7Office of the Law Revision Counsel. 26 U.S. Code 6655 – Failure by Corporation to Pay Estimated Income Tax It uses the same underpayment rate from Section 6621. This one can bite even when the annual Form 8804 ultimately shows the correct total, because the installments themselves were late.
Reasonable-Cause Relief
The IRS evaluates penalty relief case by case. To qualify, the partnership has to show it exercised ordinary care and was still unable to pay on time.8Internal Revenue Service. Penalty Relief for Reasonable Cause The review focuses on the person who had authority to submit the return or deposit.
Grounds the IRS generally accepts include fires or natural disasters, inability to access records, serious illness or death of the responsible person, and system failures that blocked a timely electronic payment. Grounds that generally do not qualify include lack of knowledge of the filing requirement, reliance on a tax professional, and simple oversight.8Internal Revenue Service. Penalty Relief for Reasonable Cause “We didn’t know Section 1446 applied to us” is not a defense the IRS tends to accept, so a partnership that has any foreign partner should put the four Form 8813 dates on its compliance calendar from day one.