"Cheapest" sounds like a single number. It isn't. What you actually pay to invest in ETFs from Belgium depends on three things most comparisons quietly ignore: how you invest (a lump sum or a monthly contribution), what you buy, and the hidden Belgian cost stack sitting on top of every trade. We're talking TOB, currency spreads and custody fees.
Get those wrong and the "cheapest" broker on paper can quietly become the most expensive one in practice.
This article breaks down the real all-in cost of investing with the main brokers available to Belgian investors and tells you which one actually wins on price. If you want a broader answer covering interface, product range and support, read our best broker in Belgium for ETFs guide instead. This one is purely about cost.
TL;DR: cheapest broker for a €300/month ETF investor
Let's imagine this scenario: €300 invested every month into IWDA (iShares Core MSCI World, Irish-domiciled, accumulating, EUR-traded on Euronext Amsterdam). Total invested after a year is €3,600.
Total year-1 cost includes TOB at 0.12% per trade, applied to each monthly €300 purchase. The TOB rate is the same across all brokers for IWDA, the difference is who files it.
MeDirect wins as it offers "commission-free" ETF investing. On raw numbers, Trade Republic, DEGIRO and Curvo come within a few euros of each other at the top. Re=Bel, Saxo and MEXEM form a tight middle cluster around €28/year. Bolero and Keytrade are roughly 3–5× more expensive at this scale, but all auto-handle Belgian taxes for you. The cheapest broker on a year-1 spreadsheet isn't necessarily the cheapest after TOB paperwork and the behaviours each broker nudges you into. Let's dig into this further.
The real cost of a Belgian ETF broker
Let's take a closer look at all the fees you may pay through a broker in buying your ETF.
1. Transaction fees
The headline number. Ranges from €1 (commission-free brokers) to around €6 per ETF order at the Belgian banks. One important nuance: a broker with a €1 fee that nudges you into 12 trades a year costs €12 in commissions. A broker with a €5 fee that lets you batch once a quarter costs €20. Frequency matters as much as the fee itself.
2. TOB: 0.12% or 1.32%, and why fund domicile decides
This isn't directly a broker cost but it's something to keep in mind. Belgium charges a "taxe sur les opérations de bourse / beurstaks" on every ETF purchase and sale. The rate depends on the fund's domicile and share class:
- 0.12%: Irish or Luxembourg-domiciled ETFs not registered in Belgium (most of them). This is what you want.
- 1.32%: Belgian-registered distributing funds. Over 10× the standard rate. Avoid.
- 0.35%: Belgian-registered capitalising funds.
On a €10,000 purchase, that is a €12 tax versus a €132 tax. The choice of ETF can dwarf the choice of broker.
Most brokers auto-calculate and pay the TOB for you: Bolero, Keytrade, Saxo, Re=Bel, DEGIRO and MEXEM all do. Trade Republic is the main exception: you file it yourself monthly via MyMinfin. Miss the deadline and you pay fines. That admin burden is a real cost for you as an investor.
3. Currency conversion
Buy a USD-listed ETF like VOO or VTI and your broker converts EUR to USD on every trade. Spreads vary widely: Interactive Brokers charges around 0.002% (negligible), Bolero charges 1.5%, Keytrade around 1%. On a €10,000 purchase, that is €0 versus €150 on a single trade.
The simple fix: stick to EUR-traded, Irish-domiciled ETFs (IWDA, VWCE, EUNL, SPYI) and currency cost drops to zero on any broker. This article assumes you're doing that.
4. Custody and inactivity fees
Good news: none of the main brokers on this list charge ongoing custody fees on ETF positions. DEGIRO charges €2.50 per year per foreign exchange you use (waived for your home exchange). Keytrade has a dormant-account fee if your account goes inactive. Bolero, Trade Republic, MEXEM, Belfius and Saxo charge nothing.
5. Withdrawal and deposit fees
Usually €0 for SEPA transfers. Watch for MEXEM's one-free-withdrawal-per-month rule and Trade Republic's instant withdrawal fees on some tiers.
6. Other taxes on ETFs
A 30% capital gains tax applies to the bond component of any ETF holding more than 10% bonds, payable on sale. Belgium also levies a 10% capital gains tax on profits from selling ETFs, with the first €10,000 per year exempt. Neither is a broker fee, but your broker determines how painful both are to deal with. Belgian brokers handle the calculation and withholding automatically. With a self-reporting broker like Trade Republic, both are your responsibility and neither calculation is straightforward.
Broker-by-broker fee breakdown
MeDirect
- ETF transaction fee: €0 (for now)
- TOB: auto-handled
- Custody: €0
- Best for: Investors who want zero-commission ETF trading with Belgian tax handled. Note: no automated savings plan, so monthly DCA requires manual orders each time.
Trade Republic
- ETF transaction fee: €1 flat
- TOB: self-reported (you file monthly via MyMinfin)
- Custody: €0
- Best for: Cost-obsessed investors who don't mind filing TOB themselves
DEGIRO
- ETF transaction fee: €1 on the "core selection" ETFs, €3 otherwise
- TOB: auto-handled
- Custody: €2.50/year per foreign exchange (waived for home exchange)
- Best for: Investors who want cheap trades and Belgian tax paperwork handled
MEXEM
- ETF transaction fee: ~€1.95 on a €1,000 ETF order
- TOB: auto-handled
- Custody: €0
- Best for: Investors who want Interactive Broker's platform with Belgian tax handled automatically
Re=Bel (Belfius)
- ETF transaction fee: €2 on a €1,000 ETF order (scales up with larger orders)
- TOB: auto-handled
- Custody: €0
- Best for: Belfius customers who want everything in one place and surprisingly competitive on cost for small-to-mid ETF orders
Saxo
- ETF transaction fee: €2 on a €1,000 ETF order
- TOB: auto-handled
- Custody: €0 on ETF positions
- Savings plans: €2/month fee if you use automated recurring buys
- Best for: A low-fee Belgian-handled alternative to Bolero
Bolero
- ETF transaction fee: €5 on a €1,000 ETF order (ETF Playlist pricing)
- TOB: auto-handled
- Custody: €0
- Best for: Investors who want KBC's Bolero platform and are willing to pay a premium over Saxo or Re=Bel for it
Keytrade Bank
- ETF transaction fee: €5.95 on a €1,000 ETF order
- TOB: auto-handled
- Custody: €0 (dormant-account fee applies if inactive)
- Best for: Existing Keytrade customers
Curvo
- Transaction fee: none
- Annual fee: 0.6% all-in (tiered down for larger portfolios)
- TOB: exempt (no TOB applies to Curvo's fund structure)
- Rebalancing: automatic, no extra cost
- Best for: Investors who want a diversified, rebalanced portfolio with zero tax paperwork
Why the cheapest broker isn't always the right broker
Two things a spreadsheet doesn't capture.
First, commission-free brokers nudge behaviour. Trade Republic is cheap for disciplined DCA and a trap if zero-friction trading turns you into a stock-picker. Its self-reported TOB also means a monthly admin task you cannot afford to forget.
Second, a single ETF is not a portfolio. The cheapest broker that lets you buy IWDA is not necessarily cheaper than a slightly more expensive solution that gives you a properly diversified, rebalanced portfolio, if the diversification adds more value than the fee difference costs.
If either of those concerns apply to you, the cheapest broker in this article is not the right answer. Read our best broker in Belgium for ETFs and best broker for beginners guides instead.
Conclusion
Cheapest is not always best. The right broker depends on how much you value your time, how disciplined you are, and whether you want to build a portfolio yourself or have it done for you.
If pure cost is your priority: MeDirect wins. Trade Republic and DEGIRO are the other options for DIY ETF investors, at around €16 and €19 per year respectively for a €300/month investor. Trade Republic is marginally cheaper but requires you to file TOB yourself. DEGIRO handles it for you. MEXEM, Re=Bel and Saxo are a reasonable middle ground if you want a more established platform without paying Belgian bank prices. Bolero and Keytrade are hard to justify on cost alone.