In short: a European regulation (DAC8) requires Bitstack to hold the tax identification number of every client resident in the EU and to send certain information to the tax authorities each year.
You must enter your number in the app before January 1, 2027.
This does not create any new tax and does not change how you use Bitstack.
What is DAC8?
DAC8 is a European Union directive (Directive 2023/2226) in force since January 1, 2026. It extends to crypto-assets the automatic exchange of tax information that already exists for bank accounts between EU countries.
In practice, crypto-asset platforms regulated in Europe, such as Bitstack, must identify their clients’ tax residence and report their transactions to the tax authorities. It applies to all players in the European market, not just Bitstack.
Why is Bitstack asking for my tax identification number?
The tax identification number is the data that allows the authorities to match the information they receive to the right person. DAC8 requires us to collect it, along with your country of tax residence, for every client resident in the EU.
What information does Bitstack send, to whom, and when?
Each year, Bitstack sends the following to the French tax authority (DGFiP), which then shares it with the tax authority of your country of tax residence:
your identity information: last name, first name, address, date of birth, country of tax residence and tax identification number;
an annual summary of your crypto-asset transactions: amounts bought, sold and transferred.
The first report, covering the year 2026, will be sent in 2027.
Does this change my taxes?
No. DAC8 does not create any new tax and does not change your filing obligations, which remain those of your country of residence.
If you have questions about your tax situation, please contact your tax authority or a tax advisor: Bitstack does not provide tax advice.
How do I enter my number in the app?
Open the Bitstack app.
Go to Settings → Personal information → Tax residence.
Confirm your city of birth and your country of tax residence, then enter your number.
It takes less than 2 minutes. You can edit this information at any time in the same place.
Where can I find my tax identification number?
It depends on your country of tax residence:
Country | Name of the number | Format | Where to find it |
France | Tax number (NIF) | 13 digits | At the top of your income tax return and your tax notice; in your personal account on impots.gouv.fr |
Belgium | National register number (NN / Rijksregisternummer) | 11 digits | On the back of your ID card; on your ISI+ card or official documents |
Spain | NIF (DNI for Spanish nationals, NIE for foreigners) | 8 digits + 1 letter (DNI); 1 letter + 7 digits + 1 letter (NIE) | On your DNI, your residence card (TIE) or your Agencia Tributaria documents |
Portugal | NIF (Número de Identificação Fiscal, or “número de contribuinte”) | 9 digits | On your Cartão de Cidadão; on the Portal das Finanças |
Italy | Codice fiscale | 16 characters (letters and digits) | On your tessera sanitaria, on the back of your electronic ID card, or on the Agenzia delle Entrate website |
Germany | Steuerliche Identifikationsnummer (Steuer-ID / IdNr) | 11 digits | On your Einkommensteuerbescheid, your Lohnsteuerbescheinigung, letters from the Finanzamt or your ELSTER account |
Netherlands | Burgerservicenummer (BSN) | 9 digits | On your passport, ID card or driver’s license; on MijnOverheid |
If you are a tax resident of another EU country, enter the tax identification number issued by that country. The OECD publishes a country-by-country factsheet describing the format and the documents where the number appears.
What happens if I don’t enter my number?
If your number has not been entered 60 days after you sign up for the app, we will be required to suspend all bitcoin operations on your account:
purchases of any kind: one-off purchases, recurring purchases and Round-ups;
sales;
transfers;
Stackback accumulation, which will no longer be credited on your card payments.
Your bitcoin and your euros remain yours, and you keep access to your account. Your recurring purchases and Round-ups are paused, not deleted: everything resumes normally as soon as the information is completed, with no further action needed.
I don’t have a tax identification number. What should I do?
This can happen in some situations, for example if you have just moved to a country and your number has not been issued yet. In that case, indicate it in the app and state the reason: our compliance team will review your situation and get back to you if needed.
As soon as you receive your number, enter it in the app.
I’ve just moved or my tax residence has changed. What should I do?
Update your country of tax residence and your number in Settings → Personal information → Tax residence. It is important that this information stays accurate: it determines which tax authority your information is sent to.
Is my data safe?
Yes. Your number is stored in encrypted form and is only used to meet our regulatory obligations. Once entered, it is never displayed in the app, nor shared for any other purpose.