When it comes up
Your US LLC files 1042-S if it has paid any non-US person US-source income during the year. “US-source” and “withholding” are narrow categories for most of our customers — a disregarded LLC paying a non-US contractor for services performed outside the US generally has no 1042-S obligation, because the income is not US-source.
Where 1042-S does bite:
- Paying US-source dividends, interest, royalties to a non-US person.
- Paying a non-US contractor for services performed in the US.
- Payments to a non-US entity that owns US-situated assets.
Companion forms
- Form 1042 — the summary return filed alongside the 1042-S set.
- W-8BEN / W-8BEN-E — the certification the recipient provides to establish foreign status and (optionally) claim a treaty rate.
Timing
Due 15 March following the calendar year of payment. [VERIFY — current IRS instructions]
See also: W-8BEN, Form 1099-NEC.