RDTOH and US shareholders of Canadian corporations

Canada’s refundable dividend tax on hand (RDTOH) mechanism is one of the more elegant pieces of the Canadian tax system, but it creates genuine complexity for US persons who own Canadian private corporations. The system exists to prevent Canadians from parking investment income inside a corporation to defer personal tax, and it does this by collecting a refundable tax at the corporate level that gets returned only when dividends flow out to shareholders. For a Canadian resident, the math works out reasonably well. For a US person, you’re layering CFC rules, GILTI, foreign tax credit limitations, and qualified dividend classification on top of a system that was never designed with a cross-border shareholder in mind.

This guide walks through the mechanics of RDTOH, its interaction with US tax obligations, and the planning levers available to cross-border shareholders.

What is RDTOH and why does it exist?

RDTOH is a notional account that tracks refundable taxes a Canadian-controlled private corporation (CCPC) has paid on certain types of income. Canada refunds this tax to the corporation at a rate of $1 for every $2.61 of taxable dividends the corporation pays to its shareholders. The mechanism enforces the integration principle: corporate income should ultimately bear roughly the same total tax burden whether earned directly by an individual or flowed through a corporation.

Without RDTOH, a CCPC owner could earn investment income (interest, rents, royalties, taxable capital gains) inside the corporation at a combined federal-provincial rate that’s lower than the top personal rate, and simply leave the money there. The refundable tax tops up the corporate rate on that income to approximate the personal rate, then gives it back when the income actually reaches a person’s hands as a dividend. It’s a forced integration mechanism.

The statutory foundation sits in Part I and Part IV of the Income Tax Act (ITA). Part I’s refundable tax applies to investment income earned directly by the CCPC, while Part IV applies to portfolio dividends the CCPC receives from other corporations.

How do the two RDTOH pools work?

Since the 2019 tax year, every CCPC tracks two separate RDTOH balances: eligible RDTOH (eRDTOH) and non-eligible RDTOH (nRDTOH). The eligible pool accumulates from Part IV tax paid on eligible dividends received from connected or non-connected corporations. The non-eligible pool accumulates from Part I refundable tax on investment income and from Part IV tax on non-eligible dividends received.

The split matters because it controls what type of dividend the corporation must pay to trigger a refund from each pool. Eligible RDTOH can only be recovered by paying eligible dividends (those designated from the corporation’s general rate income pool, or GRIP). Non-eligible RDTOH is recovered by paying non-eligible dividends, though there’s an ordering rule: if a corporation pays eligible dividends and has a balance in its eRDTOH, the refund comes from eRDTOH first. Only when eRDTOH is exhausted can eligible dividends trigger a refund from nRDTOH.

This two-pool system was introduced alongside the 2018 passive income rules to prevent a planning technique where CCPCs would earn passive income (generating refundable tax), then pay eligible dividends (which carry a lower gross-up and personal tax rate) to recover that refundable tax. The result was an effective tax rate on passive income that was lower than intended.

How does Part IV tax feed into RDTOH?

Part IV tax is a 38.33% refundable tax on taxable dividends a private corporation receives from another Canadian corporation, subject to exceptions for dividends from connected corporations where the payer obtained a dividend refund. The tax is computed under ITA section 186 and flows into the appropriate RDTOH pool based on the character of the dividend received.

If your CCPC holds shares in a publicly traded Canadian company and receives a $10,000 dividend, the corporation pays $3,833 in Part IV tax. That $3,833 gets added to its eRDTOH (assuming the dividend from the public company is an eligible dividend). The corporation can recover that $3,833 by paying $10,000 in eligible dividends to its own shareholders ($10,000 / $2.61 = $3,831, rounded).

For dividends from connected corporations (generally, corporations where the recipient holds 10% or more of voting shares), Part IV tax is only assessed to the extent the paying corporation received a dividend refund as a result of paying that dividend. This prevents the same pool of refundable tax from being duplicated up a corporate chain.

How does Part I refundable tax work?

Part I refundable tax adds 10.67% on top of the regular corporate tax on a CCPC’s “aggregate investment income,” which includes interest, rents, royalties, and taxable capital gains (net of allowable capital losses). Combined with the base federal rate of 38% minus the 10% federal abatement, plus a 6.67% additional tax on investment income, the total federal rate on passive income inside a CCPC reaches approximately 38.67%, of which 30.67% is refundable.

The 30.67% refundable portion flows into the non-eligible RDTOH pool. This is the mechanism that prevents passive income deferral inside a CCPC. At a combined federal-provincial rate often exceeding 50% on investment income (before the refundable portion is considered), the effective corporate rate on passive income, after RDTOH recovery, drops to roughly 19-23% depending on the province. That’s still higher than the small business rate on active income, which is the intended result.

The calculation lives in ITA section 129(3), where “refundable portion” is defined. For cross-border shareholders, the key point is that this refundable tax sits inside the corporation until dividends are paid, and it’s the non-eligible RDTOH pool that grows.

How does a corporation get its RDTOH back?

The corporation recovers RDTOH by paying taxable dividends to its shareholders. The refund formula under ITA section 129(1) returns the lesser of 38.33% of all taxable dividends paid in the year, or the corporation’s RDTOH balance at year end. In practical terms, for every $2.61 of taxable dividends paid, the corporation gets $1 back from its RDTOH account.

The ordering rules matter here. If the corporation pays eligible dividends, the refund comes first from eRDTOH. If the corporation pays non-eligible dividends, the refund comes from nRDTOH. A corporation can designate dividends as eligible only to the extent of its GRIP balance, so the type of dividend it can pay (and which pool it can tap) depends on the composition of its income history.

What are GRIP and LRIP?

GRIP (General Rate Income Pool) tracks the cumulative income a CCPC has earned at the general corporate tax rate (i.e., income that did not benefit from the small business deduction). LRIP (Low Rate Income Pool) tracks income taxed at the small business rate. These pools determine what type of dividend the corporation can designate when paying its shareholders.

A CCPC can designate a dividend as “eligible” only up to its GRIP balance. Eligible dividends carry a higher gross-up (38%) and a higher dividend tax credit for Canadian resident shareholders, reflecting the higher corporate tax already paid on that income. Non-eligible dividends carry a lower gross-up (15%) and lower credit, reflecting the small business deduction benefit.

For a US shareholder, the eligible vs. non-eligible distinction has less direct impact because the US doesn’t use Canada’s gross-up and credit mechanism. What matters on the US side is whether the dividend qualifies as a “qualified dividend” under IRC section 1(h)(11), which depends on holding period and treaty eligibility rather than the Canadian designation. However, the designation still matters indirectly because it determines which RDTOH pool gets tapped and affects the total Canadian tax the corporation pays (which in turn affects available foreign tax credits).

GRIP accumulates from the corporation’s net income that was taxed at the general rate, plus eligible dividends received from other corporations, minus eligible dividends paid. A brand-new CCPC that earns only active business income eligible for the small business deduction will have a GRIP of zero and can only pay non-eligible dividends.

How does the US classify Canadian dividends?

The US taxes dividends from Canadian corporations as either qualified dividends (taxed at the preferential long-term capital gains rate of 0%, 15%, or 20% plus the 3.8% net investment income tax) or ordinary dividends (taxed at the shareholder’s marginal rate up to 37% plus NIIT). Canadian corporate dividends can qualify for the lower rate because Canada has a comprehensive income tax treaty with the United States.

To receive qualified dividend treatment under IRC section 1(h)(11), three conditions must be met: the dividend must be paid by a corporation organized in a country with a qualifying treaty (Canada qualifies), the stock must meet a holding period requirement (held for more than 60 days during the 121-day period centered on the ex-dividend date), and the dividend must not be from a passive foreign investment company (PFIC). The PFIC test can be a trap for CCPCs with significant passive income relative to total assets or gross income.

There’s an important interaction with CFC rules here. If the CCPC is a controlled foreign corporation (CFC), previously taxed income that was included in the US shareholder’s income under Subpart F or GILTI is not taxed again when distributed as a dividend. These distributions come out of the shareholder’s previously taxed income (PTI) accounts. Only the portion of the dividend that exceeds PTI gets tested for qualified dividend treatment.

For more on treaty-based treatment, see our guide to the US-Canada tax treaty.

What happens when a CCPC is a CFC?

A US person who owns (directly, indirectly, or constructively) more than 50% of a Canadian corporation’s voting power or value makes that corporation a controlled foreign corporation under IRC section 957. This triggers annual reporting on Form 5471 and potential current-year income inclusions even if no dividend is paid.

The CFC classification means the US shareholder must include certain categories of income on their personal return in the year earned, not the year distributed. Subpart F income under IRC section 951 captures passive income (foreign personal holding company income), including the same categories that generate RDTOH in Canada: interest, dividends, rents, royalties, and capital gains. So the investment income that Canada taxes at the corporate level (with a refundable portion sitting in RDTOH) also gets pulled into the US shareholder’s current-year income.

This creates a timing mismatch. Canada collects corporate tax (including the refundable portion) and holds the RDTOH until a dividend is paid. The US includes the underlying income immediately through Subpart F. The US shareholder can claim foreign tax credits for the Canadian corporate tax paid (via the deemed-paid credit mechanism), but the refundable portion sitting in RDTOH is a complication, because it’s tax that has been “paid” to Canada but will later be refunded.

How do GILTI rules affect CCPC owners?

Global intangible low-taxed income (GILTI) under IRC section 951A is a separate inclusion that applies to CFC income not already captured by Subpart F. For a CCPC, active business income (the income eligible for Canada’s small business deduction) typically falls under GILTI rather than Subpart F, because it’s not passive income.

GILTI is calculated as the CFC’s tested income minus a deemed return on tangible assets (qualified business asset investment, or QBAI). For many CCPCs, especially service businesses with few tangible assets, QBAI is small, so most of the active income ends up as a GILTI inclusion. Individual US shareholders don’t get the Section 250 deduction that corporate shareholders receive, so GILTI is taxed at full ordinary rates for individuals.

The foreign tax credit for GILTI is limited to 80% of the deemed-paid taxes, and it falls in a separate basket that can’t be mixed with other foreign tax credit categories. If the CCPC’s active income is taxed at the small business rate (approximately 12-13% combined federal-provincial on the first $500,000), the effective Canadian tax rate is well below the US rate, and the GILTI inclusion will generate net US tax. This is one of the core pain points for US persons owning CCPCs: the small business deduction that benefits Canadian-resident shareholders actually creates a US tax gap for American owners.

The interaction with RDTOH is indirect but real. RDTOH applies to investment income, not active business income. But the total tax picture for the shareholder includes both GILTI on active income and Subpart F on passive income, and the foreign tax credits from each sit in different baskets. Planning that reduces RDTOH (by paying dividends to trigger the refund) also increases current-year dividend income on the US return, which affects the shareholder’s overall marginal rate and NIIT exposure.

Does the RDTOH refund create a US tax cost?

Yes, in most cases. The RDTOH refund itself is not income to anyone: it’s a reduction of Canadian corporate tax. But the dividend that triggers the refund is a taxable event for the US shareholder. The net effect depends on whether the dividend is coming out of previously taxed income (PTI) or represents “new” income to the US shareholder.

If the underlying passive income was already included in the shareholder’s US return as Subpart F income, the dividend distribution should be excludable under IRC section 959 as a distribution of PTI. In that case, the RDTOH recovery is largely neutral from a US perspective: the dividend triggers the Canadian refund without creating additional US tax, because the income was already taxed in the US. However, the foreign tax credit picture changes, because the Canadian corporate tax on that income is now lower (by the amount of the RDTOH refund), which means the available deemed-paid foreign tax credit is also lower.

If the dividend exceeds PTI (for example, because the corporation has retained earnings from periods before the US shareholder acquired the shares, or from income categories not subject to Subpart F), the excess is taxable as a dividend in the US. Qualified dividend treatment would apply if the conditions under IRC section 1(h)(11) are met, giving a maximum federal rate of 23.8% (20% plus 3.8% NIIT). But that’s still a real cost, and it’s the price of recovering the RDTOH.

How should you time dividends?

Dividend timing is the primary planning lever for cross-border RDTOH optimization. The goal is to align Canadian dividend refund recovery with US tax years where the shareholder has sufficient foreign tax credit capacity (or low enough marginal rates) to absorb the dividend income without excessive US tax leakage.

A few principles help frame the analysis. First, if Subpart F has already pulled investment income into the US return, paying a dividend to recover the related RDTOH is often a clean move: the dividend comes out of PTI (no additional US tax), and the RDTOH refund reduces the corporation’s cash tax cost. The shareholder loses some deemed-paid credit, but the cash in hand is worth more. Second, in years where the shareholder has excess foreign tax credit carryovers (from high-tax Canadian income in prior years), paying larger dividends can be advantageous because the US tax on the dividend is partially or fully offset by those credits. Third, deferring dividends in years where the shareholder has high US-source income (pushing them into higher brackets or triggering NIIT) and accelerating them in lower-income years can reduce the lifetime tax cost.

The Canadian side has its own timing considerations. RDTOH balances don’t expire, but they don’t earn interest either. Leaving money in RDTOH is an interest-free loan to CRA. For a CCPC with a large nRDTOH balance, there’s a real cost of capital in delaying recovery, especially if the corporation could reinvest the refunded cash.

Provincial tax rates also affect timing. Some provinces have lower personal dividend tax rates than others, and if the shareholder is a Canadian resident (dual resident scenarios exist), the province of residence matters for the integration math.

Is salary or dividends the better choice?

For US persons who are both shareholders and employees of their CCPC, the salary-versus-dividend split is the foundational planning decision, and RDTOH adds another variable to the analysis. Salary is deductible to the corporation (reducing corporate income and therefore RDTOH accumulation on investment income), taxable to the individual, and generates RRSP room for Canadian residents. Dividends are not deductible, come from after-tax corporate income, and trigger RDTOH recovery.

From a pure RDTOH perspective, paying salary reduces the corporation’s investment income (because salary is an expense), which means less Part I refundable tax and a smaller RDTOH buildup. Paying dividends recovers existing RDTOH but creates shareholder-level tax. The optimal mix depends on the corporation’s income composition: if most income is active business income eligible for the small business deduction, there’s minimal RDTOH anyway, and the salary-dividend decision turns on other factors (CPP contributions, RRSP room, corporate retained earnings needs).

For US tax purposes, salary from a Canadian corporation is foreign earned income, potentially eligible for the foreign earned income exclusion (FEIE) under IRC section 911 if the shareholder lives in Canada, or simply foreign-source income generating foreign tax credits if they live in the US. Dividends, as discussed, may be qualified (lower rate) or ordinary, and interact with CFC/GILTI rules. The relative advantage of salary vs. dividends on the US side depends on the shareholder’s total income profile, residency, and credit position.

In practice, most cross-border practitioners model three or four scenarios (all salary, all dividends, 50/50 split, and an optimized split) for each tax year and pick the combination that minimizes total two-country tax. There’s no universal answer, and it shifts year to year as income levels, rates, and credit balances change.

What does the passive income cap mean?

Starting in 2019, a CCPC’s access to the small business deduction (SBD) begins to phase out when the corporation (and its associated group) earns more than $50,000 of aggregate investment income (AII) in a year. The SBD is fully eliminated at $150,000 of AII. This interacts with RDTOH because the same passive income that generates refundable tax also threatens the small business rate on the corporation’s active income.

The math is punitive: for every $1 of AII above $50,000, the business limit (the amount of active income eligible for the SBD) is reduced by $5. A CCPC with $80,000 of investment income loses $150,000 of its $500,000 business limit, meaning $150,000 of active income shifts from the small business rate (approximately 12%) to the general rate (approximately 26.5% combined). The additional tax on that $150,000 of active income is roughly $21,750, which is a steep cost.

For a US shareholder, losing the SBD has a secondary effect: active income taxed at the general rate generates GRIP, allowing the corporation to pay eligible dividends. It also means higher Canadian corporate tax on the active income, which produces larger deemed-paid foreign tax credits for GILTI purposes. In some cases, the loss of the SBD actually improves the cross-border tax position because the higher Canadian tax rate reduces the GILTI gap. This is not a reason to deliberately generate passive income, but it’s a factor to model.

Investment income that generates RDTOH and investment income that triggers the SBD grind are the same pool. Planning to keep AII below $50,000 (through timing of capital gains realizations, use of holding companies, or converting passive investments to active business income) serves both purposes: it preserves the SBD and limits RDTOH buildup.

What about Section 55 anti-avoidance?

ITA section 55 is an anti-avoidance rule that can recharacterize intercorporate dividends as capital gains (or, after the 2018 amendments, as proceeds of disposition). It targets situations where dividends are used to strip value from a corporation and reduce capital gains that would otherwise arise on a sale of shares. The 2018 changes significantly broadened Section 55’s reach and made it relevant to more routine intercorporate dividend planning.

Before 2018, Section 55 generally applied only when a “purpose” test was met. The 2018 amendments introduced a mechanical test: if an intercorporate dividend exceeds the “safe income on hand” attributable to the shares, the excess can be recharacterized. Safe income on hand is, roughly, the retained earnings of the corporation that have been subject to tax. The calculation is complex and requires tracking income, taxes paid, and non-deductible amounts on a share-by-share basis.

For RDTOH planning, Section 55 matters because intercorporate dividends between connected corporations are a common tool for managing RDTOH pools. For example, a shareholder might use a holding company structure where the operating CCPC pays dividends to a holding company, which then pays dividends to the individual. Part IV tax on connected-corporation dividends is limited (as discussed above), so this structure can move RDTOH balances without triggering the full 38.33% Part IV tax. But if Section 55 recharacterizes the intercorporate dividend as a capital gain, the RDTOH recovery breaks down, and unexpected tax costs arise.

US shareholders with multi-entity Canadian structures need to be particularly careful here. A recharacterization under Section 55 changes the character of income for Canadian purposes, but the US may not respect the same recharacterization (depending on whether the US treats it as a dividend under its own classification rules). This can create mismatches in foreign tax credit categories and Subpart F character.

Cross-border RDTOH planning is genuinely difficult and fact-specific, but several principles consistently apply. Track your RDTOH pools meticulously: your Canadian T2 return (Schedule 3) shows the current eRDTOH and nRDTOH balances, and these need to be reconciled against your US reporting (Form 5471, Schedule H for previously taxed income). Model the total two-country tax cost before paying any dividend, because a dividend that recovers $10,000 of RDTOH but generates $5,000 of net US tax has a real benefit of only $5,000. Use salary to manage the corporation’s AII and keep it below $50,000 where possible. Don’t ignore provincial rate variations. And if you’re structuring with a holding company, get the Section 55 analysis done before any intercorporate dividends flow.

This guide is general information, not tax advice for your specific situation. Which points apply, and how, depends on your facts.