If your US multi-member LLC issued you a Schedule K-1 for the first time and you are a Canadian resident, the typical Google answer tells you to check Box 1, find your tax residency, and file Form 1040-NR. That answer skips the two questions that actually drive your tax bill. Which boxes on the K-1 matter for a foreign partner versus a US partner, and what is the difference between the §1446(a) withholding the partnership already did on your annual income and the §1446(f) withholding that would apply if you sold your interest. This post is the box-by-box decoder, the §1446(a) versus §1446(f) split, and the Form 8804 plus 8805 routing into your 1040-NR.
30-second answer
A foreign partner Schedule K-1 routes differently from a US partner K-1. Box 1, ordinary business income, drives §1446(a) annual withholding at 37 percent for individuals or 21 percent for foreign corporate partners on effectively connected income, called ECI. The partnership files Form 8804 with the IRS and gives you Form 8805 as your withholding receipt, which you attach to Form 1040-NR Schedule NEC to claim the credit. §1446(f) is separate. It is a 10 percent withholding on the amount realized when you sell or transfer your partnership interest, not on annual income. Box 16, formerly the international tax box, now points you to Schedule K-3 for foreign tax credit and treaty positions. Box L, the tax-basis capital account, can go negative for a foreign partner faster than for a US partner because §1446(a) withholding reduces basis without an offsetting distribution. The Canada-US treaty Article VII can override §1446(a) if your activity does not rise to a US permanent establishment, but you must file 1040-NR plus Form 8833 to claim it, and the partnership will still withhold unless you provide a valid Form W-8BEN before each distribution.
Why a foreign partner reads the K-1 differently
A US-resident partner reads the K-1 as a worksheet that flows into Form 1040. Box 1 lands on Schedule E. Box 14, self-employment earnings, lands on Schedule SE. Most boxes either flow to a known line or are ignored if zero. The K-3 is often skipped entirely.
A Canadian foreign partner reads the same form for different purposes. Three of those purposes have no analog on the US side.
First, you need to confirm the partnership classified you correctly as a foreign partner. Item E of the K-1 shows the partner identifying number. If the partnership listed your SSN or a US address for you and you do not have either, the K-1 was probably misclassified, and the §1446 withholding was probably skipped. That gap shows up later as a notice rather than a refund.
Second, you need to reconcile the §1446(a) withholding shown on Form 8805 against the income reported on the K-1. The two numbers should tie. The 8805 box 10 withholding equals your share of §1446(a) tax for the year. The K-1 income in boxes 1, 2, 3, and other ECI items should match the gross figure the partnership withheld on. A mismatch usually means the partnership treated some income as non-ECI without telling you, or applied a treaty rate that you did not authorize.
Third, you need to identify which boxes are informational only versus which boxes trigger a US tax position. For a US partner, almost every box is potentially taxable. For a foreign partner, roughly half the K-1 is informational because the income type does not create US tax for a non-resident, or the treaty exempts it.
Box-by-box decoder for the foreign partner
The table below maps every line on the standard Schedule K-1 (Form 1065) for tax year 2025 against four columns. Foreign-relevance flags how often the box matters to a Canadian non-resident. Routing target shows where the number actually lands on your filings.
| Box | Description | Foreign relevance | Routing target |
|---|---|---|---|
| Box 1 | Ordinary business income or loss | High. ECI triggers §1446(a) withholding | Form 8805 box 9, then 1040-NR line 8 via Schedule NEC or Schedule E |
| Box 2 | Net rental real estate income | High. Default FDAP, but §871(d) election converts to ECI | 1040-NR Schedule E if §871(d) elected, otherwise reported gross on Schedule NEC |
| Box 3 | Other net rental income | High if connected to US trade or business | 1040-NR Schedule NEC, treated as ECI if PE present |
| Box 4a | Guaranteed payments for services | High. Treated as US-source compensation if services performed in US | 1040-NR line 1a, plus §1446(a) on the ECI portion |
| Box 4b | Guaranteed payments for capital | Medium. Treated as interest-like FDAP | Subject to §1441 withholding at 30 percent or treaty rate, not §1446 |
| Box 4c | Total guaranteed payments | Informational sum | Not separately filed |
| Box 5 | Interest income | Low. Most US-source partnership interest is FDAP, often portfolio-interest exempt | 1040-NR Schedule NEC line 1, treaty Article XI usually exempts |
| Box 6a-6c | Ordinary, qualified, and dividend equivalents | Medium. FDAP at 30 percent, treaty Article X reduces to 15 percent for individuals | 1040-NR Schedule NEC, withhold via §1441 not §1446 |
| Box 7 | Royalties | Medium. FDAP at 30 percent, treaty Article XII reduces to 10 percent | 1040-NR Schedule NEC, §1441 withholding |
| Box 8 | Net short-term capital gain or loss | Low. Generally not US-taxable for non-residents unless US real property (FIRPTA) | Schedule NEC line 9, or 1040-NR Schedule D if FIRPTA |
| Box 9a-9c | Net long-term capital gain, collectibles, unrecaptured §1250 | Low to medium. FIRPTA-taxable if US real property partnership interest, called USRPI | Schedule NEC or §1445 withholding via Form 8288-A |
| Box 10 | Net §1231 gain or loss | Medium. ECI if connected to US trade or business | 1040-NR Schedule E or Form 4797 |
| Box 11 | Other income | Varies. Read Schedule K-3 to identify the source | Depends on income code |
| Box 12 | §179 deduction | Low. Generally not usable on 1040-NR without ECI | Reduces Box 1 if ECI |
| Box 13 | Other deductions | Medium. Some codes flow to 1040-NR if ECI | Reduces Box 1 or claimed separately |
| Box 14 | Self-employment earnings | None. Self-employment tax does not apply to Canadian non-resident under IRC §1402(b) | Skip entirely. See companion article on SE tax exemption |
| Box 15 | Credits | Low. Most US tax credits are not refundable to non-residents | Schedule 3 of 1040-NR if applicable |
| Box 16 | Schedule K-3 indicator | High for foreign partners. Flags that K-3 is attached | Read K-3 in full for treaty positions, foreign tax credit, and §1446 reconciliation |
| Box 17 | AMT items | Low. AMT rarely applies to non-residents | Form 6251 if AMT triggered |
| Box 18 | Tax-exempt income and nondeductible expenses | Informational | Capital account adjustment only |
| Box 19 | Distributions | High. Cash distributions that exceed your basis trigger gain recognition | 1040-NR Schedule D, basis tracking |
| Box 20 | Other information | Varies by code. Look for codes V, Z, AH | Some flow to Form 8995 or other credits |
| Box 21 | Foreign taxes paid or accrued | Medium for FTC mapping | Skipped on US side, but feeds T2209 foreign tax credit on the Canadian T1 |
The boxes you cannot ignore as a Canadian foreign partner are 1, 2, 4a, 16, 19, and L. Box 16 is the gateway to Schedule K-3, and K-3 is where the partnership tells you which income items are ECI versus FDAP and which qualify for treaty relief. Treat K-3 as a required read, not a supplement.
§1446(a) versus §1446(f): the two withholdings that look alike
The single most common confusion in foreign-partner LLC content is treating §1446(a) and §1446(f) as one thing. They are different taxes on different events, with different rates and different forms. Reading them side by side makes the distinction durable.
| Aspect | §1446(a) annual ECI | §1446(f) sale of interest |
|---|---|---|
| Trigger event | Partnership earns ECI allocable to a foreign partner during the tax year | Foreign partner sells, exchanges, or otherwise transfers a partnership interest |
| Rate, individual partner | 37 percent under §1446(b)(2)(A), referencing the highest §1 rate | 10 percent of the amount realized under §1446(f)(1) |
| Rate, foreign corporate partner | 21 percent under §1446(b)(2)(B), referencing the highest §11 rate | 10 percent of the amount realized |
| Who withholds | The partnership | The transferee, or buyer, of the partnership interest |
| Form filed by withholding agent | Form 8804 plus Form 8805 to each foreign partner | Form 8288 plus Form 8288-A for amount realized over the threshold |
| Form the partner attaches to 1040-NR | Form 8805 | Form 8288-A |
| Frequency | Quarterly via Form 8813, reconciled annually on 8804 | One-time at the sale event |
| Statutory basis | §1446(a), enacted 1986 | §1446(f), added by TCJA Pub. L. 115-97 §13501(c)(2), effective for transfers after December 31, 2017 |
| Reclaim path | Credit on 1040-NR line 25g via attached 8805 | Credit on 1040-NR Schedule D via attached 8288-A |
| Treaty interaction | Article VII may reduce or exempt if no US PE, claim via Form 8833 plus W-8BEN | Article VII can apply if the partnership does not own US real property, but the 10 percent rate is at the amount-realized level so claiming relief usually means filing 1040-NR to seek refund |
The reason §1446(f) matters for a partner who has not sold yet is that the partnership must withhold 10 percent on any cash distribution that exceeds your share of partnership liabilities, if a sale transaction was triggered. In practice for an active Canadian foreign partner who is not exiting, you only encounter §1446(a). The §1446(f) layer activates the year you sell. The companion piece on multi-member LLC Operating Agreements covers the clause you put in the OA to control how 1446(f) is handled when a partner exits. See /blog/mmllc-operating-agreement-non-resident-llc for the clause text.
Form 8804 and 8805 routing in plain English
The two forms work as a pair. Form 8804 is the partnership's annual return for §1446 tax. Form 8805 is the per-partner statement. Treat 8805 as the foreign-partner equivalent of a W-2 for withholding purposes, except the underlying income is reported on K-1 not on 8805.
Form 8804 lives at the partnership. It aggregates every foreign partner's ECI share and the total §1446(a) tax paid quarterly via Form 8813. The partnership files 8804 with the IRS by the partnership's tax return due date, generally March 15 for calendar-year partnerships, or September 15 with extension.
Form 8805 is your copy. The partnership issues one 8805 per foreign partner per tax year. The box that matters most for your 1040-NR is box 10, the withholding credit. That number flows to Form 1040-NR line 25g as a payment, which reduces the balance due or increases the refund.
The reconciliation flow looks like this. Box 1 of K-1 shows your ECI ordinary income, say $80,000. Form 8805 box 9 shows the partnership's calculation of your §1446(a) tax base, which usually equals the same $80,000. Box 10 shows the §1446(a) tax withheld, which is $29,600 at 37 percent for an individual. On your 1040-NR, you report the $80,000 as ECI on Schedule E or Schedule NEC depending on the activity, calculate your actual US tax on graduated rates, and then claim the $29,600 as a withholding credit. If your actual tax is lower than the withholding, you get a refund. If higher, you owe the difference.
The 8805 attaches to the front of 1040-NR. Many first-time filers staple K-1 instead of 8805. The IRS does not credit §1446(a) withholding from a K-1 alone, so a missing 8805 means a missing credit and a notice for the full balance due.
The season calendar that ties partnership returns to your 1040-NR
For a Canadian foreign partner, four dates govern the year. Missing any one of them either delays your refund or generates a penalty.
| Date | Event | What you need to do |
|---|---|---|
| March 15 | Partnership Form 1065 plus 8804 due, K-1 plus 8805 issued to partners | Confirm you received both K-1 and 8805. If missing, request from the partnership immediately |
| April 15 | Original 1040-NR deadline for non-residents with US wages, also FBAR deadline for partners with US bank signing authority | Most Canadian SMLLC and MMLLC partners do not have US wages, so April 15 is not your deadline. FBAR may still apply if you have signing authority on a US Mercury or Relay account |
| June 15 | 1040-NR deadline for non-residents without US wages | File 1040-NR with 8805 attached, or file Form 4868 for an October 15 extension |
| September 15 | Extended Form 1065 plus 8804 due | If the partnership extended, K-1 and 8805 should arrive by this date |
| October 15 | Extended 1040-NR deadline | File the final 1040-NR with all attachments |
The interlocking risk is that a partnership extension to September 15 leaves a foreign partner with only 30 days between receiving the K-1 plus 8805 and the October 15 1040-NR deadline. If your partnership routinely extends, plan to file your own 1040-NR extension to October 15 automatically and use the gap for the actual filing, not for chasing the partnership.
Treaty Article VII routing for ECI that should not be taxed
A common scenario for a Canadian partner in a US MMLLC is that the partnership classifies your share of business income as ECI and withholds §1446(a) at 37 percent. If your underlying activity does not rise to a US permanent establishment under treaty Article V, the Canada-US treaty Article VII says the US cannot tax the business profit at all, even though the income is technically ECI under US domestic law.
The mechanics for claiming Article VII without losing the withholding to inertia work like this.
First, deliver Form W-8BEN to the partnership before the partnership's first distribution of the year. The W-8BEN is in your name as the individual partner, not the LLC, because the partnership is fiscally transparent for treaty purposes. Check the treaty claim box and reference Article VII. If you fail to deliver W-8BEN, the partnership defaults to 37 percent withholding even if your treaty position is valid.
Second, the partnership may still withhold pending IRS guidance on partner-level treaty claims for §1446(a). Many partnerships withhold at the full rate to protect themselves from secondary liability under §1463 and let the partner reclaim via 1040-NR.
Third, file 1040-NR with Form 8833 attached. Form 8833 is the treaty-based return position disclosure. It documents your Article VII claim and the reason the US permanent establishment threshold is not met. Without 8833, the IRS may disallow the treaty position on examination.
Fourth, claim the §1446(a) withholding shown on 8805 box 10 as a payment on 1040-NR line 25g. With Article VII applied, your US tax on the ECI is zero, and the entire withholding becomes a refund.
The path takes 16 to 24 weeks for the refund to issue after filing, longer if 8833 triggers a manual review.
Box L tax-basis capital account: the negative-balance trap
Item L on the K-1 shows your capital account using the tax basis method. For a US partner, a negative capital account is a sign of distributions that exceeded contributions plus allocated income. For a foreign partner, the same number can go negative through a different mechanism that catches non-residents off guard.
§1446(a) withholding reduces your tax-basis capital account in the year the withholding occurs, just like a distribution would. The partnership pays the IRS your share of §1446(a) tax. From a basis perspective, that payment is treated as a distribution to you, even though the cash went to the Treasury, not to you. If the partnership also distributes cash to you in the same year, the combined basis reduction can exceed your allocated income plus prior basis.
A worked sequence:
| Item | Amount | Tax-basis capital account effect |
|---|---|---|
| Opening capital account, January 1 | $50,000 | Starting balance |
| Allocated ordinary business income (Box 1) | +$80,000 | $130,000 |
| §1446(a) withholding paid by partnership (Form 8805 box 10) | -$29,600 | $100,400 |
| Cash distribution received during year (Box 19, code A) | -$120,000 | -$19,600 |
A negative tax-basis capital account does not in itself create a US tax event for a foreign partner during the holding period. It becomes a problem at sale or liquidation. Under §731 and §752, a distribution that drops your basis below zero, including a deemed distribution from debt relief at sale, triggers gain recognition. The amount of gain equals the negative basis at the moment of the event.
The practical control is to monitor item L every year and have the partnership reduce distributions in years where §1446(a) withholding has already consumed the bulk of allocated income.
Schedule K-3: the foreign partner's required reading
Schedule K-3 is the partnership-level reporting of items of international tax relevance. For a US partner, K-3 is often optional or skipped. For a foreign partner, K-3 is the document that distinguishes ECI from FDAP, identifies the source of each income stream, and reports the partnership's position on treaty allocation.
K-3 has 13 parts. The parts that a Canadian foreign partner reads in detail are:
- Part I, partnership-level information, confirms the partnership's general international filing position.
- Part II, foreign tax credit limitation, allocates the partner's share of US-source and foreign-source income, which feeds the FTC calculation on the Canadian T1 via T2209.
- Part IV, information for FDAP withholding, lists the FDAP income types and the rate the partnership applied, including treaty reductions.
- Part X, foreign partner's distributive share of §1446 amounts, reconciles to Form 8805 and confirms the §1446(a) tax base.
The companion article on ECI versus FDAP classification, at /blog/eci-vs-fdap-canadian-llc-member, walks through the seven income types and how K-3 reports each one. Read K-3 before filing 1040-NR. Filing without reading K-3 routinely leads to misreporting on Schedule NEC.
What other guides leave out for non-resident partners
Most online K-1 guides target a US-resident audience. The four angles that do not appear in the typical SERP top five for this query are the ones that matter most for a Canadian partner.
First, the §1446(a) versus §1446(f) split is usually compressed into one paragraph or omitted entirely. The AI Overview at the time of writing references the two sections but does not separate the annual ECI mechanism from the sale-of-interest mechanism. A foreign partner who reads the compressed version often files 1040-NR with the wrong attachment.
Second, the Box L tax-basis trap from §1446(a) withholding-as-deemed-distribution is rarely covered. US-partner guides focus on the cash distribution side. The withholding side is where foreign partners actually run into the negative basis.
Third, the treaty Article VII override path requires Form 8833 plus Form W-8BEN delivered to the partnership before distributions. Most K-1 guides cover Form 8833 as a downstream filer detail without naming the upstream W-8BEN dependency that controls the withholding behavior in the first place.
Fourth, the season calendar shows three different deadline interactions, March 15 partnership, June 15 non-resident 1040-NR, October 15 extension, that none of the SERP top five lay out as a single timeline.
FAQ
What are the taxes for a non-resident owner of a US LLC?
A non-resident owner of a US LLC pays US federal income tax on effectively connected income at graduated rates, with §1446(a) withholding by the partnership at 37 percent for individuals or 21 percent for foreign corporations. FDAP income, such as US-source royalties and portfolio dividends, is taxed at 30 percent gross or a treaty-reduced rate via §1441. State taxes may apply where the LLC has nexus. Canadian residents also report worldwide income on the T1 and can claim a foreign tax credit on T2209 for US tax paid. See the companion article on foreign tax credit mapping for the CRA side.
Do I need to file Schedule K-1 with Form 1065?
The partnership, not the partner, files Form 1065 and attaches all partner K-1s to the IRS return. As a partner, you receive your K-1 by March 15, or September 15 if the partnership extended. You do not file the K-1 separately. You use the K-1 to prepare your own return, Form 1040-NR for a Canadian non-resident, and you attach Form 8805 to that return to claim the §1446(a) withholding credit.
Is Schedule K-1 the same as Form 1065?
No. Form 1065 is the partnership's annual income tax return filed with the IRS. Schedule K-1 is a per-partner statement issued from the partnership to each partner, summarizing that partner's share of partnership income, deductions, and credits. Form 1065 is one filing per partnership. Schedule K-1 is one filing per partner per year.
Where is Schedule K-1 on Form 1065?
Schedule K-1 is a separate form, not a section inside Form 1065. The partnership attaches one K-1 per partner to the back of Form 1065 when filing with the IRS. The partnership also issues a copy directly to each partner. Look for the heading "Schedule K-1 (Form 1065)" in the upper-left corner. The partner's name and identifying number are in Part II, item E.
How do I file Canadian income tax on US Schedule K-1?
As a Canadian resident, you report your share of LLC income on the T1 as foreign business income or foreign investment income, depending on whether CRA treats your LLC as a flow-through or as a corporation. CRA generally treats an LLC as a corporation for Canadian tax purposes, which can create a classification mismatch with the US pass-through treatment. The US tax shown on your 1040-NR can be claimed as a foreign tax credit on T2209, but treaty Article XXIX-A and Article IV(7)(b) limit the credit in some structures. See the companion article on LLC CRA-IRS mismatch.
Does the partnership withhold §1446(f) on annual income or only on sale?
§1446(f) withholding applies only when a foreign partner sells, exchanges, or transfers a partnership interest. It does not apply to annual income allocations. The 10 percent rate under §1446(f)(1) is on the amount realized at the sale event, not on operating income. The annual income withholding is §1446(a), at 37 percent for individuals or 21 percent for corporate foreign partners. The two sections are often confused because they share the §1446 numbering. The TCJA-added §1446(f) became effective for transfers after December 31, 2017.
How to act on what you found
If you received your first K-1 and 8805 last week, the first action is to verify the two documents reconcile. Box 1 of K-1 should match the income base on Form 8805, and the withholding on 8805 box 10 should equal that base times 37 percent for individuals or 21 percent for foreign corporate partners. If the numbers do not tie, ask the partnership for a corrected K-1 or 8805 before you file 1040-NR.
If you expect the partnership to issue you a K-1 this year and you have not yet delivered Form W-8BEN with treaty claim, do so before the next distribution. Without W-8BEN on file, the partnership withholds at the full §1446(a) rate even if your activity is treaty-protected.
If your LLC is multi-member with a Canadian partner and the Operating Agreement does not address §1446(a) or §1446(f) explicitly, the OA is generic and will create disputes at distribution time. The companion article on MMLLC Operating Agreements walks the eight clauses that fix this. The companion piece on paying yourself from a Canadian-owned LLC shows how the §1446(f) matrix interacts with the OA when a partner exits.
Need a cross-border CPA to review your first K-1 and the 8805 reconciliation before filing 1040-NR? Get a free quote and we will walk you through the box-by-box read for your specific partnership.
This article is general business information, not legal or tax advice. Have a licensed cross-border CPA review your final 1040-NR, 8805, and treaty positions before filing.