Crypto Exchange Self-Certification: No Answer by 1 January 2027 and Trading Stops

Anyone who opened a crypto account before 2026 will hear from their exchange over the coming months. What it asks for is a tax self-certification: your country of tax residence, your tax identification number, and a confirmation that the details are correct. Ignore it and you do not lose your balance, but you do lose the ability to trade with it. That is what the German Crypto Asset Tax Transparency Act, the KStTG for short, lays down, and the cut-off date is 1 January 2027.

German coverage of the new reporting duty is almost entirely about what the tax office will learn about you. That is one half of it. The other half asks something of you, and the consequence is not a query from the tax office but an account you can no longer trade on. This article explains the obligation, its deadlines, its consequences, and what we measured on 17 August 2026 about how providers communicate it in public.

Crypto Exchange Self-Certification: What the KStTG Requires From You

The KStTG transposes the EU directive DAC8 and the OECD's CARF standard into German law. It obliges crypto-asset service providers to identify their users for tax purposes and to report certain transactions once a year to the Federal Central Tax Office. Sections 4 to 6 set out how that identification works: the provider has to obtain a self-certification, check it for plausibility, and document it.

In practice the self-certification comes down to a handful of details. You are asked for the country or countries in which you are tax resident, the corresponding tax identification number, and an explicit confirmation that the information is accurate. Some providers also ask for your place of birth. The effort involved runs to a few minutes in the app. The problem is not the effort but that many people take the request for marketing and click it away.

Section 7(2) KStTG: The 1 January 2027 Deadline Applies to Existing Customers

The statutory wording is brief and unambiguous here. Section 7(2) reads: "In the case of a crypto-asset user who entered into a business relationship with the provider by 31 December 2025, the provider shall complete the measures under sections 4 to 6 by 1 January 2027."

What matters is whose deadline this is: the provider's, not yours. The exchange has to be finished by that day. From this follows a calculation that does not appear in the statute but does follow from the deadlines. If the block under section 8 takes effect at the earliest 60 and at the latest 90 days after the initial request, and if a reminder and a formal notice come before that, then the requests have to go out by autumn 2026 at the latest. That is an inference from two deadlines and not an announcement by any provider; nobody has named a mailing date. Only the direction is solid: the post arrives before the cut-off, not after it.

You can read the full text of the Crypto Asset Tax Transparency Act yourself. Sections 7 and 8 sit there alongside the due diligence duties that precede them.

New or Existing Customer: Why 31 December 2025 Is the Dividing Line

The law knows two groups of people with differently strict rules. For everyone who began their business relationship by 31 December 2025, the transitional deadline quoted above applies, running to 1 January 2027. For everyone after that, section 7(1) applies, and it is stricter: there, identification has to be complete before a reportable transaction is carried out at all.

The Federal Central Tax Office describes the same sequence in its procedural guidance and puts it this way for new customers: "As a rule, obtaining the self-certification and confirming its plausibility are required before reportable transactions are carried out." For existing customers the authority names the same cut-off date as the statute. So anyone who has opened an account since January 2026 will already know the query; anyone who has held their account for years often still has it ahead of them.

Section 8 KStTG: Request, Reminder, Formal Notice, Then the Block

Enforcement is staged. First the provider requests the details. If no answer comes, a reminder follows, then a formal notice. Only when nothing comes of that either does the final stage take effect. The decisive sentence in section 8(3) is that the provider must then, "at the latest after 90 days have elapsed, but not before 60 days have elapsed since the original request, prevent the crypto-asset user from carrying out reportable transactions through the provider."

Two details here are easily skipped. First, the block is not a matter of discretion for the provider but a duty. It cannot be waived as a goodwill gesture. Second, the clock runs from the original request, not from the formal notice. Anyone who ignores the first email and only pays attention at the notice stage has already used up part of the window.

Between 60 and 90 Days: How Quickly the Block Follows the Request

The span is deliberately framed as a corridor. Before 60 days have elapsed the provider may not block; after 90 days it must. What happens inside that span depends on each provider's internal procedure. That fixes a window of roughly two to three months between the first request and the point at which trading ends.

For your planning that means this: once the first request arrives, you have plenty of time, but not unlimited time. Deal with it the same evening and the matter is closed. Leave it lying around and you need to remember when it came.

What the Block Hits: Reportable Transactions, Not the Whole Account

Precision pays off here, because the shorthand "the exchange freezes your money" is misleading. The law speaks of preventing the user from carrying out reportable transactions. What is meant are the operations that fall under the reporting duty, essentially exchange and trading activity. Withdrawing your own balance to your own bank account is not automatically part of that.

One provider describes exactly this distinction in its public help centre: users who do not supply their tax details first receive reminders; after that the account can be restricted so that trading ends while withdrawing the balance remains possible. How an individual provider implements that technically is its own decision, and the law only prescribes the lower limit. You should not rely on it: an account you can only empty is not a working account.

The Block Is Reversible: What Section 8(3), Second Sentence, Guarantees

Unlike a supervisory measure, this is not a permanent state. The law expressly provides for the way back: the business relationship can be resumed as soon as the user supplies the information requested. So anyone who only takes notice once the block hits has to submit the details afterwards and is then able to trade again.

That takes the drama out of the process that some quarters attach to it, but it changes nothing about the practical nuisance. Between the block and reactivation lies a processing time nobody guarantees. Anyone who wants to react to a price move during that time cannot.

The 17 August 2026 Survey: 24 Help Articles Across Six Providers

How well prepared are investors for this process? Rather than estimate, we measured it. On 17 August 2026 we queried the publicly searchable help centres of six crypto providers whose help interface is openly accessible, and evaluated every article that names DAC8, CARF, the self-certification, the tax identification number, or the Crypto-Asset Reporting Framework in its title or body. We checked Bitvavo, Bitpanda, BISON, Gemini, Luno and Bybit. cryptoticker.io carried out this survey itself on 17 August 2026.

The result in numbers: five of the six providers carry a relevant help article at all, 24 in total. At one provider the search found none. The distribution is uneven: Bitpanda alone accounts for eleven articles, mostly explaining where to find the tax number in the respective country, including separate texts for Germany, Austria and Switzerland. BISON, the provider run by Boerse Stuttgart, carries four, Bitvavo four, Gemini three, Luno two.

How Current the Pages Are

The revision dates stood out. At BISON, four of the relevant articles were updated between 11 and 16 August 2026, at Bitvavo two on 12 and 13 August. These pages are in motion, then, while the cut-off date draws closer. What a provider changes in the process is not something the date tells you; we only read off the time of the last change, not the change itself.

Not One Help Article Checked Names 1 January 2027

The most striking finding is an absence. In none of the 24 articles did the statutory cut-off date for existing customers appear. Neither "1 January 2027" nor the German equivalent nor 31 December 2026 turned up. One provider phrases the deadline for existing users along the lines of "by 2027", without naming a day.

The picture is similar for the mechanics of the block. Exactly one provider names any day-count deadline in this context, namely 60 days. That deadline applies there expressly to accounts opened from January 2026 onwards, so to new customers under section 7(1). The corridor of 60 to 90 days from section 8(3), which starts the actual clock for existing customers, appeared in none of the texts checked.

No accusation against the providers follows from this, and we make none. The law obliges them to obtain the self-certification; it does not oblige them to name a cut-off date in a public help article. The request itself reaches you by email or as a prompt in the app anyway, not through a help page. So the finding says something else: anyone who wants to inform themselves in advance will not find the deadline everything hangs on in the public explainers.

Tax ID, Tax Residence and Place of Birth: Which Details Are Required

The German tax identification number is an eleven-digit number that the Federal Central Tax Office assigns to every person registered in Germany. You will find it on tax assessments and on the notification sent when it was issued. Anyone who cannot find it can request it again from the Federal Central Tax Office; it does not change over the course of a lifetime.

Alongside the number, your tax residence is queried, meaning the country in which you are registered for tax. At one provider, your place of birth with town and country is part of it too. In every case the final step is a confirmation that the details are correct. It is precisely that confirmation which turns a data query into a self-certification within the meaning of the law, and section 6 KStTG governs when it is valid.

If you are wondering what happens to these details: the provider enters them into the annual report to the Federal Central Tax Office. This article here deals with the opposite direction: what you have to give the provider so that it can report at all.

Multiple Tax Residences: Why Moving Doubles the Declaration

Anyone tax resident in more than one country has to state every country concerned and every associated number. That affects more people than you might assume: cross-border commuters, emigrants in the year of their move, people with a second home abroad. One provider notes expressly in its help centre that all numbers have to be on file, and describes how further entries can be added later.

The same provider mentions a practical side effect at this point that is worth reading: for trading shares and ETFs on the same platform it applies a restriction where more than one tax residence is on file. That is not a requirement of the KStTG but a decision by the provider, though it does show that the declaration can have effects beyond the reporting duty. Anyone with multiple residences should read their provider's terms with that in mind. You will find an overview of the firms licensed in Germany in our comparison of regulated crypto exchanges.

Genuine Request or Phishing: How to Check the Message From Your Exchange

An email that asks for your tax number and residence and threatens an account block is the template for a scam attempt. That the genuine request sounds exactly the same does not make things easier. The rule against it is plain and applies regardless of how credible a message looks: do not click any link in the message, but open the app or type your exchange's address yourself. Genuine requests appear there too, usually as a notice banner or as a step in the account area.

Two further markers help. No exchange needs your password, your two-factor code or your wallet recovery words for the self-certification; anyone asking for those wants something else. And a genuine request never leads to a payment. The self-certification costs nothing.

How the Cut-Off Date Relates to Other Deadlines Now Running

1 January 2027 is not the only date currently running towards crypto accounts. Several providers have announced market exits, delistings and migrations this summer that take effect considerably earlier; we have compiled them in an overview of the exchange deadlines now running. The difference matters: those deadlines force you to withdraw balances, this one only asks for a declaration.

The two are connected nonetheless. Anyone closing accounts or moving holdings right now should check in the same pass whether the tax details are complete on the accounts that stay. Doing both in one go costs less time than walking the same path through the same menus twice.

Limits of This Survey: What We Could Not Check

The survey captures only what is public and machine-searchable. Four limitations belong with it.

First, the population. Of eighteen providers checked, only six offered an open, searchable help interface. The other twelve, among them several firms with large German customer bases, answered the automated request with 403, 404 or not at all. This evaluation says nothing about their help content. It therefore cannot be read as a ranking, and it is not meant as one.

Second, the channel. What was measured were help articles, not emails, app prompts or announcements in the account area. A provider may long since have named the cut-off date to its customers directly without it appearing in a help article. That is even the more likely route.

Third, the timing. This is a snapshot of a single day. Help pages change, and as the revision dates show, on this topic they are changing frequently at the moment.

Fourth, the implementation. At no point did we open an account, submit a self-certification or trigger a block. How a provider shapes the staged sequence in section 8 in detail cannot be observed from outside. The procedural guidance of the Federal Central Tax Office describes the procedure from the enforcement authority's perspective and is the second source against which we cross-read the deadlines.

Crypto Exchange Self-Certification: What to Take Away

1. Check whether you are an existing customer. If you opened your account by 31 December 2025, the transitional deadline to 1 January 2027 applies to you, and the request is probably still ahead of you. With several accounts it is worth going through all of them; our comparison of regulated crypto exchanges shows which providers are licensed in Germany.
2. Complete the declaration in the app as soon as it appears. Have your tax identification number and place of birth ready, and enter every residence if you have more than one. Go through the app or an address you typed yourself, never through a link in an email. While you are in the account anyway, export your transaction data at the same time; suitable tools are in the comparison of crypto tax software and portfolio trackers.
3. Note the date of the first request. The corridor of 60 to 90 days runs from it, not from the formal notice. If you have already hit a block, supplying the details is enough to have it lifted; switching provider is not necessary for that. Anyone who wants to switch anyway will find the alternatives in our overview of the best crypto exchanges.

(As of August 17, 2026. This article is not investment advice. Prices and fee structures change; check the terms with the provider before you buy.)