I. Introduction
Over the past decade, crypto assets have evolved from a marginal phenomenon into a mainstream component of private wealth portfolios. Belgian resident taxpayers now frequently hold cryptocurrencies alongside traditional financial assets such as shares, bonds and investment funds. As the market has matured, so too have investment strategies. Long-term holding strategies increasingly coexist with active trading approaches aimed at capturing short-term price movements.
This diversification of behaviour within a single asset class has brought to the fore an important and unresolved tax question: when a taxpayer applies different investment strategies to different crypto assets, how should realised gains be classified for Belgian income tax purposes? More specifically, does the presence of speculative crypto transactions necessarily affect the tax treatment of gains realised on long-term crypto holdings, or can these activities be assessed separately?
The answer is far from settled and has significant financial consequences. Depending on the classification adopted by the tax authorities, gains may be fully exempt, taxed at a flat rate of 33 percent as miscellaneous income, or even reclassified as professional income subject to progressive rates. Recent administrative positions suggest an increasingly strict approach, which merits closer examination.
II. The Belgian tax framework for crypto assets
Belgian tax law does not contain a specific statutory regime for crypto assets as such. Instead, gains derived from crypto transactions are taxed according to general income tax principles, based on their economic nature and the circumstances in which they are realised.
For private individuals acting outside a professional context, the starting point is the principle that capital gains realised within the normal management of private wealth are not taxable, unless a specific exception applies. This principle, which is firmly anchored in Belgian tax practice and case law, is intended to protect ordinary investment behaviour from taxation and to draw a distinction between wealth management and income generation.
Where transactions exceed the bounds of normal management, however, the resulting gains may be taxed as miscellaneous income under article 90, 1°, of the Belgian Income Tax Code 1992 (hereafter BITC92). Such income is subject to a flat tax rate of 33 percent, increased by municipal surcharges. In more extreme situations, where crypto activities display a high degree of organisation, continuity and professional expertise, the tax authorities may seek to requalify the gains as professional income, which can be taxed at marginal rates of up to 50 percent.
In practice, the key dividing line remains the distinction between normal and abnormal management of private wealth. This distinction is inherently factual and requires an assessment of all relevant circumstances.
A. Normal and abnormal management in the crypto context
In the absence of specific legislative guidance, the tax authorities and courts rely on a range of indicators to assess whether crypto transactions fall within the scope of normal private wealth management. These indicators are not cumulative and must be assessed in their entirety.
Factors that are commonly taken into account include the proportion of a taxpayer’s overall wealth invested in crypto assets, the use of leverage or external financing, the frequency and volume of transactions, the use of automated trading tools, and the taxpayer’s level of involvement and expertise. The holding period and the intention at the time of acquisition also play a central role.
Importantly, none of these criteria is decisive on its own. A long holding period does not automatically imply normal management, nor does a high transaction volume necessarily lead to a finding of speculation. The assessment remains nuanced and highly dependent on the factual context.
This complexity becomes particularly pronounced where a taxpayer combines different approaches within the same asset class.
B. Mixed crypto portfolios and administrative uncertainty
A growing number of taxpayers hold so-called mixed crypto portfolios. In such cases, certain crypto assets are acquired with a long-term investment horizon and are held over several years with limited or no disposals. Other assets, by contrast, are traded more actively in response to market fluctuations, sometimes using sophisticated tools or strategies.
From an economic perspective, there is nothing inconsistent about this approach. Traditional investment portfolios often combine long-term holdings with more dynamic components. Belgian tax law has historically accepted that different strategies can coexist within a single securities portfolio, provided that the transactions are sufficiently distinguishable.
Recent administrative guidance, however, suggests a more restrictive view when it comes to crypto assets. In a recent annual report, the Belgian Ruling Commission took the position that the investment strategy of a taxpayer should be assessed at the level of the crypto portfolio as a whole. Where part of the portfolio is managed in a speculative manner, the Commission considered that all gains realised on crypto assets should be classified as miscellaneous income, even if certain assets are held in line with a long-term investment strategy.
This approach effectively assumes that a taxpayer can pursue only one investment strategy per asset class, and that speculative behaviour in relation to some crypto assets necessarily affects the tax treatment of all others.
III. Legal analysis and points of tension
Such a globalised approach raises fundamental questions from a legal perspective. Belgian tax law does not explicitly support the idea that an entire asset class must be assessed as a single, indivisible whole. On the contrary, both doctrine and case law have consistently emphasised the importance of analysing transactions individually, with a focus on the taxpayer’s intent and behaviour at the time of acquisition and disposal.
- The Belgian Supreme Court has repeatedly held that where a transaction partially exceeds the bounds of normal management, only the abnormal component of the gain should be subject to taxation. More recent appellate case law has endorsed a similar reasoning in the context of financial assets, allowing gains to be split between a non-taxable normal component and a taxable abnormal component.
Moreover, courts have recognised that investors may compartmentalise their activities and apply different strategies to different parts of their portfolio. This reasoning has been accepted in relation to shares and other financial instruments, and there is no obvious legal justification for excluding crypto assets from this logic.
Against this background, the administrative position appears to reflect a heightened scepticism towards crypto assets rather than a strict application of existing legal principles. Whether such an approach would withstand judicial scrutiny remains an open question.
IV. Practical considerations for taxpayers
Notwithstanding these legal arguments, taxpayers must reckon with the current administrative climate. In the absence of clear and consistent case law, there is a real risk that the tax authorities will adopt a broad interpretation of speculative behaviour, particularly where crypto activities are significant in scale or sophistication.
From a practical standpoint, taxpayers who combine long-term crypto investments with more active trading should take care to clearly distinguish these activities in their operations and documentation. Maintaining separate wallets or accounts for different strategies, avoiding unnecessary operational overlap, and documenting the investment rationale at the time of acquisition can all help to support the position that different transactions should be assessed independently.
While such measures cannot eliminate risk entirely, they contribute to a clearer factual narrative and may prove decisive in the event of a tax audit or dispute.
V. The impact of the new capital gains tax
The introduction of a general capital gains tax as from 1 January 2026 adds another layer of complexity to the analysis. Under the new regime, capital gains on financial assets, including crypto assets, will in principle be taxed at a rate of 10 percent, after application of an annual exemption threshold of EUR 10,000 per taxpayer, indexed over time.
This reform does not, however, render the distinction between normal and abnormal management obsolete.
- Speculative gains may still be excluded from the 10 percent regime and taxed at 33 percent as miscellaneous income;
- While professionally organised activities may continue to fall within the scope of professional income taxation.
The legislative history explicitly states that the tax authorities must always assess whether a gain arises within the normal management of private wealth. In practice, this leaves room for interpretative divergence and potentially aggressive reassessments, particularly in the crypto sphere.
A taxpayer who declares crypto gains under the new 10 percent regime may still face challenges from the tax authorities arguing that the transactions were speculative in nature, leading to additional tax assessments, penalties and litigation. Given the inherent volatility of crypto markets and the lack of clear quantitative thresholds, the risk of inconsistent treatment cannot be excluded.
For a more in-depth analysis of the new capital gains tax as it applies to crypto assets, we invite you to consult our related article.
VI. Conclusion
The taxation of mixed crypto portfolios remains an area of significant legal uncertainty in Belgium. The notion that speculative transactions automatically taint all crypto gains is not firmly grounded in statutory law or established case law and sits uneasily with principles developed in relation to other asset classes.
Until clearer judicial guidance emerges, taxpayers and advisers must navigate a complex and evolving landscape. Careful structuring, factual discipline and a clear understanding of the applicable legal principles remain essential. As crypto assets continue to integrate into private wealth management, the coming years are likely to see an increase in tax disputes that will ultimately shape the boundaries of acceptable investment behaviour in this field.
If you have any questions regarding the tax treatment of mixed crypto investments, please feel free to contact the authors of this article, Thomas Derval and Rik Strauven.
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This newsletter does not constitute legal advice or a legal opinion. Please consult with a legal counsel of your choice before taking any action based on the information provided.