If your US LLC generates income, the first cross-border tax question is not "how much do I owe" but "what type is this income?" The IRS classifies non-resident foreign-source income as either Effectively Connected Income (ECI) or Fixed, Determinable, Annual or Periodical (FDAP) income. The classification controls everything that follows: tax rate, filing form, treaty protection, withholding, deduction availability. Most cross-border articles define the two terms but leave you to figure out which bucket your specific income falls into. This post is the decision tree by income type, with treaty article mapping and the LLC-classification effects.
30-second triage: ECI or FDAP?
Three filters distinguish the two.
| Filter | ECI | FDAP |
|---|---|---|
| Activity character | Active US trade or business | Passive: yields from capital |
| Tax basis | Net (after deductions) | Gross (no deductions) |
| Tax rate | Graduated US rates (10–37%) | 30% flat (or treaty-reduced) |
| Filing form | Form 1040-NR with Schedule C/E | Generally collected at source via withholding |
| Treaty protection | Article VII (PE required for taxation) | Articles X/XI/XII (rate reduction available) |
The single test that captures most cases: would a US business doing this same activity be considered as "engaged in a trade or business"? Active services, sales of goods through US channels, professional consulting, trading in inventory: these are ECI. Passive investment yields, royalties, rents (default), interest, dividends: these are FDAP unless tied to an active US business.
7-type income classification matrix
Most Canadian LLC operating income falls into one of seven categories. Here is the default classification and what changes the answer.
| Income type | Default classification | Modifier rules |
|---|---|---|
| SaaS / digital services | ECI if Canadian-controlled US LLC sells to US customers via active marketing | If LLC has US permanent establishment under Article V, ECI. If treaty PE absent (no fixed place of business in US), Article VII may exempt from US tax even if technically ECI |
| Consulting and professional services | ECI when work is performed in US | If services performed entirely from Canada with no US visits, generally not US-source ECI |
| Inventory sales (Amazon FBA, ecommerce) | ECI on US-source sales | Amazon FBA inventory in US warehouses creates US source. Treaty Article V (PE) may exempt if warehouse use only |
| Rental real estate | FDAP by default (30% gross) | §871(d) election converts to ECI net basis |
| Royalties (IP licensing) | FDAP | Treaty Article XII reduces rate to 10% (Canada) |
| Interest | FDAP | Treaty Article XI exempts portfolio interest |
| Dividends from US corporations | FDAP | Treaty Article X reduces to 5% (>10% ownership) or 15% otherwise |
The "modifier rules" column matters more than the default in practice. A Canadian LLC running a SaaS business with no US fixed office often pays no US federal tax under Article VII, even though the income is technically ECI in classification.
Article XXIX-A and the LLC treaty access problem
Before applying treaty rates, you must verify your LLC is treaty-eligible.
The Canada-US tax treaty Article XXIX-A (and Article IV(7)(b)) limit treaty access for fiscally transparent entities. An LLC treated as disregarded or partnership for US tax purposes is fiscally transparent. The treaty looks through to the underlying member.
Two practical consequences:
- Treaty benefits flow to the Canadian member, not the LLC: When claiming treaty rates on US-source FDAP, the W-8BEN should be in the Canadian individual member's name (with the LLC as fiscally transparent), not the LLC's W-8BEN-E.
- Article IV(7)(b) limitation applies even when fiscal transparency exists: Income paid to LLC that flows to the Canadian member may still be denied treaty rates in some structures unless certain conditions met.
Form 8832 corp election changes this. Once elected, the LLC is opaque (corporation), and the LLC's own W-8BEN-E claims treaty rates. The classification and treaty access change together.
SMLLC, MMLLC, Corp election: classification effects
Your LLC's federal tax classification determines who is subject to ECI vs FDAP rules.
Single-member LLC (disregarded entity): Income flows directly to the Canadian member. ECI/FDAP classification applied at the member level. Member files Form 1040-NR. Treaty access via Canadian member's W-8BEN.
Multi-member LLC (partnership default): LLC is a US partnership. ECI is allocated to foreign partners and triggers §1446(a) withholding (37% on foreign individual partners, 21% on foreign corporate partners). FDAP allocated to foreign partners triggers §1441 withholding (30% or treaty-reduced). Partnership files Form 1065 + Forms K-1.
LLC with Form 8832 corp election: LLC is a US corporation. ECI/FDAP classification applies at the LLC level, not the member. LLC pays 21% federal corporate tax on net income. Distributions to Canadian member trigger §1441 withholding on dividend at 30% or treaty 5%/15%. ECI/FDAP at member level is no longer an issue.
For most Canadian LLC owners with active US business activity, the SMLLC disregarded path is simplest: ECI on the active business, member files 1040-NR, treaty Article VII or PE protection.
Worked examples by business type
Concrete cases showing the classification logic.
Case 1: Toronto SaaS, no US office or staff
Canadian LLC sells SaaS subscriptions to US customers. All software development and operations from Toronto. No US employees, no US office, no US fixed place of business.
| Question | Answer |
|---|---|
| Is income US-source? | Yes (US customers) |
| Is it ECI? | Technically yes (active business, US customers) |
| Does treaty Article V (PE) apply? | Yes (no US PE) → Article VII exempts |
| US tax owed | $0 federal |
| Canadian tax owed | Full Canadian tax on worldwide income |
| Filing | Protective Form 1040-NR + Form 8833 to lock in treaty position |
Case 2: Amazon FBA, Canadian seller
Canadian LLC sells inventory through Amazon FBA. Inventory in US warehouses (multiple states).
| Question | Answer |
|---|---|
| Is income US-source? | Yes |
| Is it ECI? | Treated as such due to inventory presence + active sales |
| Does treaty PE apply? | Article V exempts use of facilities solely for storage, display, delivery |
| US tax owed | $0 federal under treaty (Amazon FBA storage qualifies as exempt PE use) |
| Canadian tax owed | Full Canadian tax |
| Filing | Protective Form 1040-NR + Form 8833 + state sales tax compliance separately |
Case 3: Vancouver real estate rental via LLC
Canadian LLC owns a rental house in Phoenix, Arizona.
| Question | Answer |
|---|---|
| Default classification | FDAP (30% gross) |
| §871(d) election filed | Converts to ECI net basis |
| Tax basis | Net rental income after deductions |
| Tax rate | Graduated US rates |
| US tax owed | Net income × graduated rate |
| Canadian tax owed | Full Canadian tax with FTC for US tax paid |
Case 4: Royalties from US licensee
Canadian LLC licenses IP to US software company. Royalties paid annually.
| Question | Answer |
|---|---|
| Classification | FDAP (passive royalty) |
| Default rate | 30% gross |
| Treaty Article XII | 10% Canada-US treaty rate |
| W-8BEN to claim | Canadian member's W-8BEN (LLC fiscally transparent) |
| US tax owed | 10% withheld at source |
Case 5: Interest from US bond portfolio
Canadian LLC holds US Treasury bonds.
| Question | Answer |
|---|---|
| Classification | FDAP (portfolio interest) |
| Treaty Article XI | Generally exempt (portfolio interest exemption) |
| Withholding rate | 0% (with proper W-8BEN) |
| Filing | None on US side beyond W-8BEN |
CRA timing mismatch on ECI
Even when ECI is properly classified on the US side, the CRA classification creates trouble.
CRA treats a US LLC as a foreign corporation. Income earned by the LLC is taxed in Canada only when distributed to the Canadian member as a dividend. So ECI taxed in the US in Year 1 may not be taxed in Canada until Year 2 (when distributed). The Foreign Tax Credit on T2209 is limited to "Canadian tax payable on the same income," which means timing mismatch can leave US tax paid as trapped FTC.
This is the core reason cross-border CPAs recommend either matching distributions to profit recognition (avoid retention inside the LLC) or using Form 8832 corp election to align classification.
Frequently asked questions
My LLC has both consulting income and rental income. Do I file once or twice? Once. Form 1040-NR can include multiple income types: Schedule C for the active business, Schedule E for rental. Each section uses its own classification (ECI for active, ECI net via §871(d) for rental). Treaty positions and any Form 8833 disclosures cover the whole return.
Does my LLC need a US EIN even if all income is FDAP collected through withholding? You need an EIN if the LLC has reportable transactions (capital contributions, distributions). For a Canadian-owned SMLLC, Form 5472 + Pro Forma 1120 must be filed each year regardless of income type, requiring an EIN.
If my income is technically ECI but treaty PE protection exempts it, should I file Form 1040-NR? Yes, file as a protective return. Mark "Treaty position" and attach Form 8833. Filing locks in the treaty position and limits the IRS statute of limitations. Skipping the protective filing leaves the statute open indefinitely if PE is later asserted.