Belgium's 2026 Capital Gains Tax: The Complete Investor's Guide

A Historic Change for Belgian Investors

On January 1, 2026, Belgium introduced a new 10% capital gains tax on financial assets. While the 33% tax on speculative gains has always existed, most private investors previously paid no tax on their normal investment gains. That era has now ended.

This guide covers everything you need to know to navigate the new rules.

The Basics: 10% Tax with €10,000 Exemption

The new tax has two key numbers to remember:

• Tax rate: 10% on net realized capital gains
• Annual exemption: €10,000 (indexed annually)

This means you only pay tax on gains above €10,000 per year. For most retail investors, this exemption provides significant protection.

What's Taxed?

The capital gains tax applies to:

The December 31, 2025 Snapshot

Here's the good news: historical gains are protected.

Any capital appreciation that occurred before January 1, 2026, is not subject to the new tax. The tax authorities will use the closing price on December 31, 2025 as your cost basis for existing positions.

Example

You bought IWDA ETF in 2020 for €50 per share. On December 31, 2025, it closed at €90. You sell in 2027 for €100.

• Taxable gain: €100 - €90 = €10 per share (not €50)
• Pre-2026 gain of €40: Tax-free forever

Exception: Higher Purchase Price

If you bought shares before 2026 at a price higher than the December 31, 2025 snapshot value, you can use your actual purchase price instead. This protects investors who bought at market highs.

This option is available for sales through December 31, 2030.

Cost Basis Methods: Hybrid Approach

Belgium uses a hybrid approach for calculating cost basis, depending on when shares were purchased.

For shares purchased before January 1, 2026, the cost basis uses the weighted average method (or the December 31, 2025 snapshot value, whichever is higher). For shares purchased from January 1, 2026 onwards, the FIFO (First In, First Out) method applies.

If you've been buying the same ETF monthly for years, when you sell, your pre-2026 shares use the weighted average cost, while post-2026 shares follow FIFO order.

Example

If you sell 15 shares in 2027 at €100:

• First 10 shares: Use Dec 31, 2025 snapshot (say €88)
• Next 5 shares: Use actual 2026 purchase price (€90)

This is where tracking becomes complex, and where Belgian Tax Calculator helps.

The €10,000 Exemption: How It Works

Annual Reset

Every year, you get a fresh €10,000 exemption. If you realize €8,000 in gains in 2026, you pay €0 in tax.

Carry-Forward Rule

If you don't use your exemption in a given year, you can carry forward up to €1,000 to the next year, with a maximum accumulation of €15,000 after 5 years of no sales.

Losses Offset Gains

Capital losses can offset capital gains within the same tax year. If you have €15,000 in gains and €7,000 in losses:

• Net gain: €8,000
• Exemption: €10,000
• Tax due: €0

Withholding vs. Self-Declaration

Belgian Brokers (Bolero, Keytrade, etc.)

Belgian brokers will withhold the 10% tax automatically. However:

• They cannot apply your personal exemption
• They cannot offset losses across brokers
• You can opt out and self-declare

Foreign Brokers (IBKR, DEGIRO, Trade Republic)

Foreign brokers will not withhold Belgian capital gains tax. You must:

1. Track all your gains and losses
2. Report them in your annual tax return
3. Apply your exemption and loss offsets yourself

Interaction with Other Taxes

Reynders Tax (30% on Bond Funds)

For funds with 10%+ bonds, the Reynders tax still applies to the bond portion at 30%. The new capital gains tax covers the remaining equity portion at 10%.

This prevents double taxation but increases complexity.

TOB (Transaction Tax)

The TOB remains unchanged. You still pay 0.12% to 1.32% on every buy and sell transaction, in addition to any capital gains tax.

Dividend Tax (30%)

The 30% dividend withholding tax is unchanged. This is why accumulating ETFs remain tax-advantaged: they avoid the dividend tax entirely.

Tax Optimization Strategies

1. Maximize Your Exemption

If possible, realize up to €10,000 in gains each year tax-free rather than letting gains accumulate.

2. Use Accumulating ETFs

Dividends reinvested inside the fund don't trigger the 30% dividend tax and compound tax-free.

3. Consider Tax-Loss Harvesting

Selling losing positions to offset gains is now a valid strategy in Belgium.

4. Document Everything

Keep records of all purchase dates, prices, and currency conversion rates. The FIFO calculations require detailed records.

How Belgian Tax Calculator Helps

Our platform is built for the new 2026 rules:

• Automatic FIFO tracking for all your positions
• Dec 31, 2025 snapshot values automatically applied
• Multi-broker aggregation for accurate loss offsetting
• Exemption tracking to optimize your tax position
• Pre-filled tax reports for your annual declaration

Start your free trial and take control of your capital gains.