A Luxembourg special limited partnership (SCSp) is normally tax transparent. Its income is attributed to its partners rather than taxed as corporate income of the partnership. A reverse hybrid mismatch can disturb that result when another country treats the same SCSp as a separate taxable person.
The mismatch matters only in defined circumstances. Article 168quater of the Luxembourg Income Tax Law targets income that would otherwise escape tax because Luxembourg and an investor jurisdiction classify the entity differently.
The mismatch in simple terms
Luxembourg attributes an SCSp’s income to its partners. A foreign investor’s jurisdiction may instead treat the SCSp as opaque, meaning taxable in its own right, and expect the partnership to pay tax.
Without a correction, Luxembourg may not tax the income because the SCSp is transparent, while the foreign jurisdiction may not tax the investor because it sees the SCSp as the taxpayer. Directive (EU) 2017/952, known as ATAD 2, required member states to address this outcome.
The Luxembourg rule has applied since the 2022 tax year. It does not make every transparent partnership taxable. Four elements must come together.
The four conditions
Article 168quater applies when the following conditions are met.
| Condition | What must be tested |
|---|---|
| Luxembourg vehicle | The entity or arrangement is formed or established in Luxembourg and is transparent here |
| Ownership | Associated non-resident enterprises hold at least 50% of voting, capital or profit rights |
| Foreign classification | Their jurisdiction treats the vehicle as a person taxable in Luxembourg |
| Untaxed income | The relevant share is not otherwise taxed under Luxembourg law or the law of another jurisdiction because of the classification mismatch |
Failing one condition keeps the income outside Article 168quater. The analysis is therefore narrower than a general comparison of tax classifications.
How the 50% threshold works
The threshold can be reached through voting rights, capital interests or rights to profits. Direct and indirect interests count. Crossing any one of the three measures can satisfy the ownership condition.
The interests of associated enterprises, linked through ownership, control or another relationship covered by the statutory definition, are added together. Two investors are not added together merely because their combined holding exceeds 50%. Their relationship and any acting-together rule within the ATAD 2 definition must first be considered.
The associated-enterprise definition also covers enterprises fully consolidated within the same group, with their assets, liabilities, income and expenses combined in full, line by line, in the group accounts. Enterprises linked by significant influence over management are also covered. A chart of ownership percentages alone may therefore be insufficient. For fund investors holding less than 10% of the units or interests and entitled to less than 10% of profits, the law presumes that they do not act together with another investor in the same fund, unless evidence shows otherwise.
Only the untaxed share enters the rule
When Article 168quater applies, the SCSp is treated as a resident taxpayer for the relevant share of net income. The tax base is limited to income that is not otherwise taxed under Luxembourg law or the law of any other jurisdiction.
If one investor jurisdiction taxes its allocated share despite treating the SCSp differently, that share is not brought into the Luxembourg reverse hybrid charge. A mixed investor base can therefore produce a partial result rather than an all-or-nothing classification.
ACD Circular 168quater/1 explains that the relevant taxpayer has a special status and identifies the income categories and filing mechanics that follow. It also confirms that the analysis is tied to the calendar year.
The collective investment vehicle exception
Article 168quater excludes a collective investment vehicle only if it meets all three conditions. It must be widely held, have a diversified portfolio of securities and be subject to investor-protection rules in the state where it is established. These conditions concern the spread of investors, the spread of investment risk and investor protection.
ACD Circular 168quater/2, issued on 12 August 2025, identifies Luxembourg undertakings under the 2010 Law on undertakings for collective investment, specialised investment funds and reserved alternative investment funds as falling within the collective-investment-vehicle definition. It then explains how the three conditions apply to other investment vehicles. An ordinary SCSp does not qualify merely because it is an alternative investment fund (AIF).
For these other vehicles, an AIF managed by a duly authorised alternative investment fund manager is generally presumed to satisfy the investor-protection condition. That does not establish the other two conditions. Wide participation is assessed through marketing to several unrelated investors and the surrounding facts. A small investor base during launch or liquidation does not necessarily prevent qualification.
The circular gives “securities” a broad meaning that includes debt claims, fund units and bank deposits as well as shares and bonds. Diversification, meaning the spread of investment risk, is assessed against the investment policy and the risks actually held. In principle, investing more than 30% of assets or commitments in one issuer fails the test unless a higher concentration has adequate justification. A concentrated co-investment SCSp therefore needs particular attention even when it appoints an authorised manager.
Monitoring changes over the fund life
The result can change after formation. Admitting investors at a closing, transferring interests or redeeming them can alter the associated-investor percentage. A new foreign tax classification can change whether an investor’s share is taxed. The portfolio can also move closer to or further from the collective-investment-vehicle conditions.
The review should therefore follow the investor register and the tax classifications used in each relevant jurisdiction. It should distinguish ownership, foreign treatment and actual taxation rather than record a single permanent label for the SCSp.
When the rule applies, the ACD electronic filing guidance identifies the combined reporting route for collective income and the corporate income tax attributable under Article 168quater. The return for year N is due by 31 December of year N+1.
Luxembourg fund formation support
To monitor the investor mix and keep the reverse hybrid analysis documented year after year.
Explore fund formation supportFrequently Asked Questions
Is every Luxembourg SCSp a reverse hybrid?
No. An SCSp is transparent under Luxembourg tax law, but the reverse-hybrid rules apply only when its ownership, foreign tax treatment and untaxed income meet all statutory conditions. The classification must be tested from the investor jurisdictions as well as Luxembourg.
What is the 50% test?
One or more associated non-resident enterprises must hold a combined direct or indirect interest of at least 50% in voting rights, capital or profit rights. Unrelated investors are not simply added together unless the associated-enterprise or acting-together rules bring them within the same analysis.
What income can become taxable in Luxembourg?
The SCSp is subject to corporate income tax only for the share of net income that remains untaxed under Luxembourg law or the law of another jurisdiction because of the classification mismatch. The reverse-hybrid rules do not automatically tax all partnership income.
