Form 1042-T is the annual summary and transmittal a withholding agent sends with paper Forms 1042-S, which report US-source income paid to foreign persons and the tax withheld. It's only for paper filing: if you file Forms 1042-S electronically, you don't use Form 1042-T. For 2025 forms, it's due with Copy A of each paper 1042-S by March 16, 2026.
This guide follows the 2025 Form 1042-T and its instructions, and the IRS 2025 instructions for Forms 1042-S and 1042, as of October 2026.
Where it fits
| Form | What it does |
|---|---|
| 1042-S | One per recipient and income type: the payment and tax withheld |
| 1042-T | Cover sheet that totals a batch of paper 1042-S forms |
| 1042 | The withholding agent's annual return of tax withheld |
Using Form 1042-T doesn't remove the need to file Form 1042. The 2025 Form 1042 instructions say you file Form 1042 even if your Forms 1042-S are filed electronically.
Paper or electronic?
The 2025 Form 1042-S instructions say Forms 1042-S must be e-filed if you're required to file 10 or more information returns in the year, if you're a partnership with more than 100 partners, or if you're a financial institution, whatever the number. If any of those apply, there's no Form 1042-T: the e-file replaces it. From January 1, 2026 you can use the IRS IRIS system to e-file 2025 Forms 1042-S, and the older FIRE system is expected to be retired on December 31, 2026.
Why you may need several 1042-T forms
Each type of paper 1042-S needs its own Form 1042-T. The type is set by four choices: chapter 4 or chapter 3, original or amended, pro rata or not, and whether you're a partnership reporting withholding that happened in the following year. The instructions list 16 combinations, for example chapter 3, original, pro rata. You can't mix chapter 4 and chapter 3 forms under one transmittal.
Line by line
| Line | What to enter |
|---|---|
| Top | Name, address, EIN and both chapter 4 and chapter 3 status codes, exactly as on Forms 1042 and 1042-S |
| 1a | 4 or 3: the chapter for every attached 1042-S |
| 1b | Original or amended, not both |
| 1c | Tick if the attached forms are pro rata |
| 1d | Number of paper Forms 1042-S attached |
| 1e | Tick if you're a partnership reporting withholding that occurred in the subsequent year |
| 1f | Tick if you're a qualified intermediary, withholding foreign partnership or trust revising pool reporting for a specific recipient |
| 2 | Total gross income from box 2 of the attached forms |
| 3a or 3b | Total tax withheld from boxes 10 and 11: line 3a for chapter 4, line 3b for chapter 3, never both |
Tick the FINAL return box only if you won't be filing any more Forms 1042-S for the year, including amended ones, on paper or electronically.
The March 16 deadline
For 2025 forms, the Form 1042-T instructions give March 16, 2026 as the date to file Form 1042-T and Copy A of the paper 1042-S forms with the Ogden Service Center, P.O. Box 409101, Ogden, UT 84409. The 1042-S instructions set the general due date as March 15, moving to the next business day when the 15th falls on a weekend or holiday, which is why the 2025 date is the 16th. Send the forms flat, not folded, and don't staple.
Copies and recipients
Attach only Copy A to Form 1042-T. Copies B, C and D go to the recipient of the income, and every copy must match the one filed with the IRS. The instructions for Form 1042-S also warn that if you e-file, you mustn't file the same returns on paper, because duplicate filing can trigger penalty notices.
When an amended 1042-S changes your 1042
If you've already filed Form 1042 for 2025 and an attached 1042-S changes the gross income or tax withheld reported on line 62c or 63e of that return, you must also file an amended Form 1042. If you haven't filed Form 1042 yet, you can send more than one Form 1042-T before you do.
Mistakes to avoid
- Using one transmittal for a mix of chapter 3 and chapter 4 forms.
- Filling in both line 3a and line 3b.
- Status codes or an EIN that don't match Form 1042.
- Paper filing when you're over the e-file threshold, or filing the same forms both ways.
The IRS estimates the average time to complete Form 1042-T at 12 minutes, so most of the effort goes into getting the batches right.
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Step by step
- Check whether you're required to e-file Forms 1042-S. If you are, stop: no Form 1042-T.
- Sort the paper Forms 1042-S into batches by chapter, original or amended, pro rata or not, and partnership subsequent-year reporting.
- Complete one Form 1042-T per batch, with matching name, EIN and status codes.
- Total box 2 for line 2 and boxes 10 and 11 for line 3a or 3b.
- Attach Copy A of each 1042-S, mail the batches flat to Ogden, and send the recipient copies.
Partnerships reporting the following year
Line 1e is for a partnership reporting withholding that occurred in the following year on a foreign partner's share of undistributed income for the prior year. The instructions say the attached Forms 1042-S should have the box 7c checkbox ticked, and these go in their own batch.
The verdict
Form 1042-T is a simple cover sheet, but it's easy to get the batching wrong. Check first whether you must e-file, sort paper 1042-S forms by chapter, original or amended and pro rata status, use one transmittal per batch, and keep the totals in line with your Form 1042.
Frequently asked questions
What is Form 1042-T?
It's the annual summary and transmittal used to send paper Forms 1042-S to the IRS.
Do I need Form 1042-T if I e-file Forms 1042-S?
No. Form 1042-T is only used to transmit paper Forms 1042-S.
When is Form 1042-T due for 2025?
The 2025 instructions say to file it with Copy A of the paper Forms 1042-S by March 16, 2026.
Where do I mail Form 1042-T?
To the Ogden Service Center, P.O. Box 409101, Ogden, UT 84409.
Can one Form 1042-T cover chapter 3 and chapter 4 forms?
No. You need a separate Form 1042-T for each type of paper Form 1042-S.
Who must e-file Forms 1042-S instead?
Anyone required to file 10 or more information returns in the year, partnerships with more than 100 partners, and financial institutions.
