Within-Year Loss Offset under Belgium’s 10% Capital Gains Tax (2026)

📅 Last updated: 17 May 2026
 ·  🏷 Topic: loss offset, calendar-year edge, category question (core question), art. 344 ITC92
 ·  🇧🇪 For: Belgian individuals who sell at both a loss and a gain in 2026

Since 1 January 2026 Belgium levies a 10% tax on realised capital gains on financial assets, above an annual exemption of €10,000 per taxpayer per calendar year (FPS Finance, accessed 2026-05-17; source in Dutch). If you realise both gains and losses in the same year, you may offset those losses against the gains — but under two strict rules: within the same calendar year and, per the prevailing practitioner reading, within the same category of financial assets. This article explains both rules, discusses the core question (FPS Finance does not explicitly confirm the category restriction) and walks through three examples. The filing-return mechanics themselves (which Tax-on-Web boxes apply, when your broker withholds, when you file yourself) live in our Meerwaardebelasting 2026: aangifte en Tax-on-Web(NL) guide.

1. What is loss offset under the 10% capital gains tax?

Loss offset (in tax-jargon Dutch: minderwaarden aftrekken — “offsetting losses”) means deducting a realised loss from a realised capital gain. “Realised” = only at the moment of the actual sale, exchange, or transfer — a position that has dropped in value on paper but has not yet been sold does not count for tax purposes.

The order of calculation under the Law of 6 April 2026 is confirmed by FPS Finance (accessed 2026-05-17) and by Bolero (accessed 2026-05-17): first add up all realised capital gains within the calendar year, deduct all realised losses from the same year, and only then apply the annual exemption of €10,000 to the net capital gain. The balance above is taxed at 10%.

💡 Don’t mix these up. The basic exemption of €10,000 per person per calendar year is the primary exemption discussed in this article — indexed for tax year 2027. The carry-forward of €1,000 per year applies to the unused slice of that same exemption (cumulatively up to €5,000 extra transferable exemption over 5 rolling years — so that the total maximum exemption can rise to €15,000; FPS Finance: “up to a maximum exemption after 5 years of 15,000 euro”) (FPS Finance, accessed 2026-05-17). Substantial shareholding (≥ 20% in a single company) falls under a separate progressive regime (1.25%-10%) with its own €1 million exemption per rolling 5-year period (KPMG Belgium, accessed 2026-05-17) — outside the scope of this article.

2. Legal framework: Law of 6 April 2026

The statutory basis is the Law of 6 April 2026, published in the Belgian Official Gazette of 21 April 2026. Mind the distinction: 3 April 2026 is the vote date in the Chamber; 6 April 2026 is the Royal promulgation date and the law’s formal title (KPMG Belgium, accessed 2026-05-17). Always refer to 6 April, even if some secondary sources still mention both dates.

The law introduces three restrictions on loss offset:

1. Realisation requirement — only losses you actually realise (sale, exchange, transfer) count. Paper losses do not.
2. Calendar-year boundary — losses can only be offset within the same calendar year as the gain. Any residual loss lapses on 31 December (see § 3).
3. Category question — the prevailing practitioner reading says: losses can only be offset within the same category of financial assets. FPS Finance does not expressly confirm this restriction (see § 4 — core question).

In scope: listed equities, ETFs, bonds, investment funds, derivatives, foreign currencies, investment gold, and cryptocurrencies. Out of scope: real estate (separate regime), pension savings, long-term savings, and the employer-sponsored group insurance (pillar 2). Professional-grade speculation remains taxed as miscellaneous income at 33% under article 90 ITC92 (PwC Belgium, accessed 2026-05-17). Personal Branch 21 within 8 years remains taxed at 30% RV (withholding tax on movable income) with no additional 10% CGT; after 8 years a surrender falls under the 10% regime (Federale Verzekering — Meerwaardetaks op Tak 21, accessed 2026-05-17; source in Dutch).

3. Within-calendar-year restriction: no carry-forward for losses

This is the heaviest rule — and the most expensive if you miss it. A loss that is not offset within the same calendar year lapses for tax purposes. There is no carry-forward for losses under the Law of 6 April 2026 (FPS Finance, accessed 2026-05-17, confirmed by Bolero — Vrijstelling en minderwaarde and DVD Tax Law, both accessed 2026-05-17).

⚠️ Not to be confused with the €1,000 carry-forward. What is transferable is the unused part of the first €1,000 slice of the basic exemption: that can be carried over to the following year (max €1,000 per year, for up to 5 years), so that the total cumulative exemption can rise to €15,000 (FPS Finance, accessed 2026-05-17). The losses themselves can never be carried forward.

Concrete consequence: calendar date is everything. Someone who sells a loss-making position on 28 December 2026 may deduct that loss from 2026 gains. Someone who waits four days and only sells after 31 December 2026 can never set the same loss against 2026 gains — it only counts toward the 2027 balance. For large amounts, that is material: 10% on €4,000 = €400 of tax, won or lost over four calendar days.

4. Same-category restriction — the core question

⚠️ No FPS circular on 2026-05-17. The FPS Finance landing page does not explicitly confirm the category restriction, and there is no FPS circular on 2026-05-17. Several independent Belgian tax lawyers and accounting firms (Loyens & Loeff, DVD Tax Law, Moore Law, LWB, SBB, Grant Thornton, KPMG, Tiberghien) read the law so that losses are only offsetable within the same category of financial assets. One retail broker (Bolero) phrases it generically without a category restriction; this stands against the reading of eight independent tax professionals. A taxpayer with a mixed portfolio is well advised to apply the restrictive reading until an FPS circular brings clarity.

Reading A — restrictive (Loyens & Loeff + DVD Tax Law + KPMG)

Losses can only be deducted from gains within the same category of financial assets. Loyens & Loeff (accessed 2026-05-17) writes explicitly: “losses…relate to the same category of financial assets”. DVD Tax Law (accessed 2026-05-17) confirms: “within the same category of financial assets”. KPMG Belgium (accessed 2026-05-17) follows the same line. Practical consequence: a loss on crypto cannot be deducted from a gain on equities; a bond loss cannot be deducted from an ETF gain. Within “equities + ETFs” (Category C in most practitioner schemes) mutual offsetting does appear to be permitted.

Reading B — liberal (FPS silence + Bolero framing)

The FPS Finance landing page (accessed 2026-05-17; source in Dutch) names no category restriction; Bolero (accessed 2026-05-17) frames loss offset generically as “loss against gain, regardless of the type of financial asset”. Under this reading a crypto loss can indeed be deducted from an equity gain. The Keytrade Bank FAQ Meerwaardebelasting (accessed 2026-05-17) likewise draws no category distinction.

What does this mean for TX-01 § 6 Example 3?

Our guide Meerwaardebelasting 2026: aangifte en Tax-on-Web(NL) shows in § 6 Example 3 an IWDA-ETF gain (+€8,000), an NN Group equity gain (+€15,000) and an Aedifica REIT loss (-€4,000). Aedifica (a Belgian REIT (GVV), a listed equity) falls under the prevailing practitioner reading (Tiberghien, Loyens & Loeff, EY, KPMG, PwC, Cazimir, all accessed 2026-05-17) into the same “listed equities / financial instruments” category as IWDA + NN Group — offsetting remains mathematically intact. None of the consulted sources name REITs (GVVs) explicitly as a separate category, but the absence of an FPS circular on 2026-05-17 means this is a convergent-implicit reading, not an FPS confirmation. Consult a licensed adviser for portfolios with large REIT positions as long as the FPS circular is outstanding. Cross-category offsets (a crypto loss against an equity gain) are where it hinges: until an FPS circular exists, this remains an uncertain position.

Wash-sale and art. 344 ITC92 — what applies when you take targeted losses?

Belgian tax law has no specific wash-sale rule (Loyens & Loeff, accessed 2026-05-17, and Curvo consensus, accessed 2026-05-17). The general anti-abuse provision of article 344 ITC92 can, however, be invoked against a purely artificial construction without economic substance (PwC Belgium, accessed 2026-05-17). Several tax practitioners hold that targeted loss-taking on its own — provided a genuine economic change of position takes place — is not considered abusive within the meaning of art. 344 ITC92. The risk zone arises only when the sole intention is tax saving and you buy back the same position within a few days without portfolio rationale.

5. Three practical examples

Example 1 — Loss and gain in the same category, same year

Lukas (single, all positions on a single Bolero account). In 2026 he realises +€14,000 on an IWDA ETF (sold June 2026) and -€3,000 on an SPY ETF (sold November 2026). Both are ETFs — uncontested same category under both Reading A and Reading B.

Line	Amount
Gross capital gain IWDA	+€14,000
Gross loss SPY	-€3,000
Net capital gain 2026	€11,000
Annual exemption	-€10,000
Taxable capital gain	€1,000
Capital gains tax 10%	€100

Example 2 — A week apart

Anouk realises in 2026 +€12,000 on an ETF sale (April) and holds in December a loss-making equity position of -€2,000. Scenario A (sale on 29 December 2026): net €10,000 − €10,000 exemption = €0 tax. Scenario B (sale on 5 January 2027): the loss only counts toward the 2027 balance; 2026 is taxed at €12,000 − €10,000 = €2,000 × 10% = €200 tax. Seven calendar days and the absence of a second sale in the same year make the difference.

Example 3 — Cross-category (the core question in action)

Sander realises in 2026 a crypto gain of +€18,000 (Bitcoin sale, June) and an ETF loss of -€5,000 (sold October).

• Under Reading A (restrictive). Crypto and ETFs are different categories. The ETF loss cannot be deducted from the crypto gain. Taxable: €18,000 − €10,000 exemption = €8,000 × 10% = €800. The ETF loss can only offset an ETF gain in 2026 — which Sander does not have — and lapses for tax purposes on 31 December.
• Under Reading B (liberal). Net capital gain 2026 = €13,000. Taxable: €13,000 − €10,000 = €3,000 × 10% = €300.

The difference between Reading A and Reading B here is €500. Conservative framing: build your expectation on Reading A and treat a more favourable outcome as a bonus once the FPS circular arrives. Document under both scenarios your purchase price, sale price and category coding (ISIN for securities, exchange-token ticker for crypto) — you will need the evidence on your 2027 return.

6. Filing-return practical impact

For anyone whose sales all run through a Belgian broker, the broker handles the 10% withholding on the gross gain per sale from 1 June 2026 (Keytrade Bank, accessed 2026-05-17, and Bolero, accessed 2026-05-17). The opt-out deadline varies sharply by broker and at several major brokers falls shortly after this article’s publication: Bolero 29 May 2026 and Keytrade 31 May 2026 close first, Belfius applies 12 June 2026, Saxo end of May to 30 June 2026. Argenta is an exception: the opt-out election window only opens on 22 June 2026 and closes on 31 August 2026. The statutory general deadline for notifying your financial institution of an opt-out runs in principle until 31 August 2026 — several brokers apply an earlier internal deadline in order to have their withholding systems ready for 1 June. Deadlines can lapse between the writing and the reading of this article — always check the current deadline directly with your own broker.

⛔ Box codes for AY 2027 not yet set on 2026-05-17. The official Tax-on-Web return form for income year 2026 is expected in Q1 2027. Do not fill in box codes blindly based on speculation.

A separate guide on reclaiming over-withholding by a broker — when gross withholding exceeds your net tax liability, typically when using multiple brokers — follows within this cluster. Until then, keep your broker statements, transaction log and category coding.

Sources & further reading

Statutory texts and FPS Finance:

• FPS Finance — Capital gains tax (accessed 2026-05-17; source in Dutch) — primary source for the €10,000 exemption, the “per person” rule, the calendar-year boundary, and the absence of a carry-forward for losses.
• Law of 6 April 2026 — capital gains tax on financial assets, BS 21 April 2026 (accessed 2026-05-17) — legislative basis (ejustice search portal; intermittently HTTP 500 at audit time).
• FPS Finance — Tax on stock-exchange transactions (TOB) (accessed 2026-05-17; source in Dutch) — TOB rates and caps, relevant for transaction costs when taking targeted losses.

• Federale Verzekering — Meerwaardetaks op Tak 21 (accessed 2026-05-17; source in Dutch) — insurer-side confirmation that Branch 21 within 8 years remains taxed at 30% RV and does not trigger an additional 10% CGT; after 8 years a surrender falls under the 10% regime. (Replaces an earlier FSMA link fsma.be/nl/tak-21, which returned HTTP 404 on 2026-05-17 — Audit-1 MATERIAL-4.)

• Wikifin — Taxes on your Belgian investments (accessed 2026-05-17; source in Dutch; page content may not be fully updated after entry into force of the Law of 6 April 2026 — check currency) — secondary-official overview via the FSMA portal.

Brokers and executors:

• Bolero — Vrijstelling en minderwaarde (accessed 2026-05-17; source in Dutch) — practitioner explanation of the order of calculation + confirmation that residual loss is not transferable.
• Keytrade Bank — FAQ Meerwaardebelasting (accessed 2026-05-17; source in Dutch) — broker withholding from 1 June 2026.

Belgian tax practitioners (secondary):

• Loyens & Loeff — Capital gains tax in Belgium becomes reality (accessed 2026-05-17) — restrictive reading of the same-category restriction.
• DVD Tax Law — Overview of the capital gains tax from 1 January 2026 (accessed 2026-05-17; source in Dutch) — confirms category restriction + €1,000 carry-forward mechanic.
• KPMG Belgium — New capital gains tax on financial assets (accessed 2026-05-17) — substantial-shareholding regime + indexation of the basic exemption + commentary on the boundaries of art. 344.
• PwC Belgium — Belgian capital gains tax changes (accessed 2026-05-17) — broader context, art. 90 ITC92 33% rate on professional speculation.

Our related articles:

• Pillar Belgische beleggingsbelastingen(NL) — overview of TOB, RV, capital gains tax, Reynders.
• Meerwaardebelasting 2026: aangifte en Tax-on-Web(NL) — the filing-return procedure step by step, including broker withholding and opt-out deadlines.
• A separate guide on the €10,000 exemption and partner-splitting follows within this cluster (in preparation).
• A separate guide on snapshot value 31 December 2025 for ETF and crypto cost-basis evidence follows within this cluster (in preparation).
• A separate guide on broker over-withholding and reclaim via Tax-on-Web follows within this cluster (in preparation).

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