📅 Last updated: 8 May 2026
· 🏷 Topic: NBB CAP, foreign account, declaration
· 🇧🇪 For: Belgian retail investors using DEGIRO/Saxo/IBKR
Anyone holding an account with a foreign broker such as DEGIRO, Saxo, Trade Republic, or Interactive Brokers must register that account with the Central Contact Point (CAP) of the National Bank of Belgium (NBB) before filing the first tax return in which it is mentioned. This is a legal obligation, not optional.
When do you have to do it?
Before you file the personal income tax return in which you mention the foreign account for the first time. The CAP declaration is filed once — not every year. When something changes (account closed, another broker added) you update it again.
After that, every year you indicate in box XIII Section A (code 1075-89) of your personal income tax return that you hold a foreign account.
Step by step
- Go directly to the NBB CAP filing portal: cappcc.nbb.be (the public NBB site at www.nbb.be only describes the scheme; you cannot file from there).
- Log in via itsme® or eID.
- Fill in for each account:
– Country where the account was opened.
– Name of the institution (e.g. “flatexDEGIRO Bank Dutch Branch” for DEGIRO).
– IBAN or account number.
– Year of opening. - Confirm and print or save the confirmation digitally.
For DEGIRO specifically: you have to file two separate declarations — one for your DEGIRO securities account and one for the linked Flatex cash account (DEGIRO + Flatex are two separate legal entities).
What if you forget?
Forgetting the NBB declaration = administrative offence. The €50 base fine for non-filing of the NBB CAP declaration is governed by article 445 CIR92; non-mention of foreign accounts on the annual personal income tax return is governed by article 307 §2/§5 CIR92 (€50–€1,250 per undeclared account per infraction). On top, a tax increase of 10% to 200% can apply to any undeclared income. With voluntary correction (declaring it yourself before the tax authority discovers it) the fine is typically low.
💡 Practical: file the NBB declaration right after opening the account — don’t wait until the tax return. Then it’s off your mind and you can’t forget it.
Which accounts fall under the rule?
- ✅ Foreign securities account (DEGIRO, Saxo, IBKR, Trade Republic, etc.)
- ✅ Foreign savings account or current account
- ✅ Foreign crypto platforms (Binance, Kraken, Coinbase) — if they act as a custodial institution. Hardware wallets and self-custody do not fall under this. From 2026 (DAC8/CARF) EU crypto platforms automatically share transaction data with the tax authority, so declaring is materially no longer optional.
- ✅ Foreign cash account linked to a securities account (Flatex with DEGIRO)
❌ Not for Belgian accounts — those are already automatically known to FPS Finance.
Link with the foreign wealth tax
For some high net worth holdings, the tax on securities accounts above €1,000,000 applies (introduced at 0.15% since 2021; raised to 0.30% by the law of 18 December 2025 for reference periods starting 1 October 2025). The NBB declaration of foreign accounts is therefore also fiscally relevant — not just administrative.
Practical tips
- Keep the confirmation of your NBB declaration. In a tax audit this is your evidence that you are in order.
- Update on every change. Closing your DEGIRO account? Update with NBB.
- Mention in box XIII Section A (code 1075-89) every year that you hold a foreign account — even if there was no income or balance change.
🔗 For the complete tax picture around foreign brokers: Belgische beleggingsbelastingen (NL) and Beleggen in België: brokers en platformen (NL).
Frequently asked questions
Do I have to declare my DEGIRO account with the National Bank of Belgium?
Yes. Every account held with a foreign broker (DEGIRO, Saxo, Trade Republic, Interactive Brokers, …) must be registered with the Central Contact Point (CAP) of the NBB before you file the first personal income tax return that mentions it. For DEGIRO you actually file two declarations: one for the DEGIRO securities account and one for the linked Flatex cash account — they are two separate legal entities.
How often do I have to file the NBB CAP declaration?
Once per account. You only update it when something changes (account closed, additional broker added). On your annual personal income tax return you do, however, have to confirm every year that you hold a foreign account, in box XIII Section A (code 1075-89).
Where exactly do I file the declaration?
On the filing portal at cappcc.nbb.be — not on the public nbb.be site, which only describes the scheme. You log in with itsme® or eID and fill in, per account, the country, the name of the institution, the IBAN or account number, and the year of opening.
What is the fine if I do not declare my foreign broker?
A €50 base fine for non-filing of the NBB declaration (art. 445 CIR92). For non-mention on your personal income tax return the fine can range from €50 to €1,250 per undeclared account (art. 307 §2/§5 CIR92), on top of a tax increase of 10 % to 200 % on any undeclared income. With voluntary correction (declaring it yourself before the tax authority discovers it) the penalties typically remain low.
Do I also have to declare my crypto account with Binance or Kraken?
Yes, if the platform is custodial (it holds the coins for you). Hardware wallets and self-custody do not fall under the rule. From 2026, under DAC8/CARF, EU crypto platforms automatically share transaction data with the tax authority, so declaring is materially no longer optional.
Does this also apply to a Belgian broker like Bolero or Keytrade?
No. Belgian accounts are already automatically known to FPS Finance — you do not have to report those yourself. The NBB declaration obligation only applies to accounts held with foreign institutions.
When should I file — right away or just before my tax return?
Right after opening the account. That way you do not forget, and you have evidence of filing in case of a tax audit. Keep the confirmation digitally or printed.
Sources
- National Bank of Belgium — Central Contact Point (CAP)
- FPS Finance — Declaring foreign accounts
- Curvo — DEGIRO declaration guide
- Article 307 ITC92 (administrative sanctions)
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