Portugal offers a valuable tax benefit for private investors who sell shares in micro and small enterprises (SMEs). When the company qualifies as an SME and is not listed, only half of the capital gain is taxed.
A recent arbitration ruling issued in late 2025 confirms that this 50% reduction applies even when the SME is based in another EU Member State. This clarification is significant for private investors with cross-border holdings, especially those involved in private equity structures in France, Spain, Germany, the Netherlands, or Italy.
This article explains the decision and its impact. It also highlights how investors can protect their tax position during the disposal of SMEs.
What Triggered the Arbitration?
A Portuguese tax resident sold an 8% stake in a French unlisted company for €200,000. The acquisition cost in 2008 was €160.
The Portuguese tax authority taxed the full gain at the standard 28% rate. It refused the 50% capital gains reduction because the company was foreign.
The taxpayer challenged the assessment in arbitration. The tribunal agreed and annulled the relevant part of the tax bill.
This ruling is now a key authority on the reduction of capital gains tax in Portugal, as well as a mechanism for SME share disposals across the EU.
Why the Tribunal Ruled in Favour of the Investor
1. The 50% reduction is an automatic benefit
The SME relief does not require prior approval. It applies when the underlying company meets the SME thresholds. These thresholds cover:
- number of workers
- annual turnover
- total balance sheet
The benefit does not depend on software limitations or the entity’s foreign status.
2. The benefit applies to EU companies under the free movement of capital
The tribunal followed well-established EU case law. Restricting SME relief to Portuguese companies breaches the principle of free movement of capital.
Therefore, the relief applies to SME shares in any EU Member State. The location cannot justify denying the reduction.
3. The SME qualification must consider the entire group
The French company held associated entities in France and Portugal. Because of this, the tribunal analysed:
- the aggregate workforce
- the combined turnover
- the combined balance sheet
The combined values remained below the SME thresholds. As a result, the investor qualified for the 50% relief.
4. The tax authority must refund excess tax and pay interest
Since the refusal of the benefit was unlawful, the authority must:
- Refund the excess tax compensation interest until the credit note is issued
This aligns with the principles governing unlawful tax assessments in Portugal.
Key Implications for Investors Selling SME Shares
1. Confirm SME status early
Because the reduction capital gains tax Portugal regime depends entirely on SME status, investors must understand the legal criteria. Portugal follows the EU definition of micro, small and medium-sized enterprises. The classification is based on objective, measurable indicators.
A. Core SME Thresholds
The SME test relies on three factors:
number of workers
annual turnover
total balance sheet
To qualify, the company must respect the relevant limits for its category.
Medium-sized enterprise
fewer than 250 workers
turnover at or below €50 million or total assets at or below €43 million
Small enterprise
fewer than 50 workers
turnover or total assets at or below €10 million
Microenterprise
fewer than 10 workers
turnover or total assets at or below €2 million
These thresholds reflect the EU Recommendation transposed into Portuguese law.
B. Understanding autonomous, partner and associated companies
SME classification depends on the company’s position within its group. Therefore, it is essential to determine whether the company is autonomous, a partner, or an associated entity.
- Autonomous companies: These are companies that do not have significant cross-holdings. They do not meet the conditions to be classified as partners or associates.
- Partner companies: These arise when a company holds at least 25% of another company’s capital or voting rights. However, this link does not give control. There are exceptions. Confident investors, such as business angels, universities, institutional investors and local authorities, may hold 25% or more without altering autonomous status.
- Associated companies exist when one company exerts a dominant influence over another. This may occur through a majority of voting rights, control of the board, shareholder agreements, or contractual influence. Associated status also applies through chains of control or when individuals act together.
C. Aggregation rules for SME calculations
When the company has partners or associates, the SME thresholds must be calculated on an aggregated basis. This means that:
Headcount is aggregated
Turnover is aggregated
Total assets are aggregated
If the group prepares consolidated accounts, those figures usually apply. This prevents under-statement of size and ensures a realistic classification.
D. Restrictions linked to public ownership
Public control affects SME status. A company generally cannot qualify as an SME if public bodies own 25% or more of its voting rights or capital. Some exceptions exist, but they are limited in scope.
E. How SME certification is obtained in Portugal
Portugal uses an electronic system managed by IAPMEI, the national agency for competitiveness. Companies can obtain official SME certification through the agency’s online platform.
The company must submit:
identification data
shareholder structure
information on workers
turnover and balance sheet
Certification is issued automatically after submission. Companies may request early certification if estimated values meet the limits, but they must later confirm the final numbers.
SME status expires if the company fails to confirm its data or no longer meets the criteria. It becomes void if based on incorrect information. Companies may submit a new application at any time.
F. Why SME classification is essential for investors
The 50%reduction of capital gains for SME share disposals depends on this classification. As a result, investors must verify the SME status before selling shares. They must also apply aggregation rules when group structures exist.
Correct SME classification can reduce the taxable gain by half. Therefore, it can materially change the effective tax burden.
Investors should keep documentation proving the company’s SME status for at least the statutory retention period. This includes IAPMEI certification and group financial statements.
2. Apply the 50% reduction even for EU companies
Investors holding shares in EU-based SMEs should assert their right to the relief. The tax authority cannot exclude foreign entities from taxation. The ruling confirms that any such exclusion would breach EU freedom of capital.
3. Review past assessments when the reduction was not applied
Investors who sold SME shares in previous tax years may have been taxed on 100% of the gain. They should consider:
- filing a claim
- initiating arbitration
- requesting repayment with interest
A review is worthwhile when the underlying company qualifies as an SME.
4. Prepare documentation to support the SME classification
The investor bears the initial burden of proof. However, this burden is modest. The investor should collect:
- financial statements
- group charts
- headcount information
Once this evidence is presented, the tax authority must justify any refusal of the relief.
Broader Impact on the Reduction of Capital Gains Tax in the Portuguese Framework
This ruling strengthens the legal foundation of the SME relief. It confirms four principles:
- The benefit applies automatically
- It covers both domestic and EU companies
- SME thresholds require material analysis
- Unlawful refusals lead to reimbursement and interest
These principles create more certainty for private investors and for advisors involved in cross-border private equity or SME M&A.
How MCS Supports Investors
MCS advises private investors on capital gains relief, cross-border share disposals, and SME classification. We help clients:
- Verify SME status using complete financial and structural data
- Prepare documentation for the 50% reduction
- Identify incorrect assessments and request refunds
- manage claims, arbitration, and negotiations with the tax authority
Our team provides clear guidance, strategic support, and full compliance assistance.
If you plan to sell SME shares in Portugal or abroad, we can assist you in securing the correct tax treatment. In addition, if you wish to understand how this ruling affects your share disposals or past capital gains, you may reach out to MCS for an assessment tailored to your investment profile.
This article provides general information on “Reduction of Capital Gains Tax in Portugal” and does not constitute tax or legal advice. Outcomes depend on individual circumstances and may vary depending on future administrative or judicial interpretations. You should seek professional guidance before making decisions based on this material.
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