The previous article was about who knows that you hold crypto and what can happen to that information when it leaks. This one looks at the other side of the same thing: what the Slovak tax administration will do with information about your crypto and how to prepare for it. It is written for an ordinary investor who buys on an exchange, sells from time to time and is not entirely sure whether their tax returns for past years are correct.
Budget 2027: rates stay, collection tightens
The government has three consolidation packages behind it. VAT went up and a financial transaction tax was introduced from 2025, and new income tax bands and higher health contributions apply from 2026. Even so, on 2 October 2026 the coalition agreed on a draft budget for 2027 with a deficit of 4.94% of GDP, roughly 7.5 billion euros. According to the draft, public debt is set to exceed 66% of GDP.
After the agreement, finance minister Ladislav Kamenický said that taxes and contributions will not rise in 2027. The deal also includes abolishing the financial transaction tax as of 31 December 2027. 2027 is an election year and the draft contains no new rate increases.
On 22 September the Council for Budget Responsibility pointed to a paradox: the state collects more in taxes and contributions than ever before and is still borrowing. At the end of September the finance ministry raised its tax revenue estimate for 2027 by about one billion euros compared with the June forecast.
For taxpayers the conclusion is simple. When rates stay the same and the state needs money, what remains is more thorough collection of taxes that already apply. This is not a new policy. The direction has been visible for some time:
| Measure | When | What it means for taxpayers |
|---|---|---|
| Tax amnesty | 1 January to 30 June 2026 | Anyone who paid an old arrear or filed a forgotten return paid no penalties or interest. The amnesty has ended and sanctions apply in full again. |
| Higher penalties | for breaches from 1 January 2026 | The penalty for not filing a return is now 100 to 30,000 euros instead of 30 to 16,000 euros. |
| Lower penalty for quick payment | from 1 January 2026 | Anyone who pays tax assessed in an audit within 15 days of receiving the decision pays two thirds of the penalty. |
| DAC8 | data collection from 1 January 2026 | Exchanges and other providers report their clients' trades to the tax administration. |
The amnesty was part of an effort to raise money within the consolidation from old tax debts as well, which the Institute for Financial Policy estimated at around 2.5 billion euros. Anyone who did not use it now deals with the same issues under the standard rules. Those are still considerably milder for people who correct a mistake themselves than for people who are audited. That is what the rest of this article is about.
What the tax administration knows about your crypto
Until the end of 2025 the tax administration had to piece together information about crypto from the bottom up. It saw bank transfers to and from exchanges, it could ask specific providers or foreign colleagues, and it had whatever the taxpayer declared in the return. This was laborious because each piece of information had to be obtained separately.
The DAC8 directive, which Slovakia transposed by Act No. 200/2025 Coll., reverses this logic. From 1 January 2026 crypto-asset service providers, mainly exchanges, brokers and custodial wallet providers, must verify their clients, record their trades and report them to the tax administration once a year. The information no longer has to be gathered from below. It arrives on its own.
| What the provider reports | Example |
|---|---|
| Who you are | name, address, date of birth, tax identification number |
| Where your account is | name and seat of the provider |
| Purchases and sales for euros | aggregate annual amount per crypto-asset and number of trades |
| Exchanges of one crypto-asset for another | aggregate annual value, measured at the time of each trade |
| Transfers off the exchange | aggregate value of transfers to wallets the provider does not manage |
The report does not list every transaction, only aggregate annual figures. That is enough for comparison with a tax return, though. If an exchange reports that you sold crypto for 40,000 euros in 2026 and the return shows nothing, the mismatch is obvious at first glance.
| Date | What happens |
|---|---|
| 1 January 2026 | exchanges start collecting data |
| 31 March 2027 | deadline for the 2026 tax return (later with an extension) |
| 31 May 2027 | exchanges report 2026 data to the Slovak tax administration |
| by 30 September 2027 | exchange of data between EU member states, including data on Slovaks using foreign exchanges |
The order of these dates matters. You file your 2026 return before the exchange sends its data. The tax administration will therefore compare the data with a return that has already been filed. If they do not match, a question from the tax office is the natural next step.
What about past years? DAC8 covers trades from 2026 onwards. Data for 2021 to 2025 will not be in the reports. Past years can still surface indirectly, however. When you sell in 2026 a crypto-asset you acquired earlier, you need to document what you paid for it. If, for example, you exchanged bitcoin for ether in 2023, that exchange was taxable in Slovakia and the acquisition price of the ether is its value on the day of the exchange. The documentation for the 2026 sale thus points to a 2023 trade that should have been in the 2023 return.
What a letter from the tax office can look like
In everyday speech the word notice is used for several different letters. They carry different weight and call for different responses.
| Type of document | What it means | How to respond |
|---|---|---|
| Request for an explanation or documents | As part of its so-called search activity, the tax office is checking whether you should have filed a return or whether your return is correct. This is not yet an audit. | Reply within the deadline, factually and with documents. |
| Notice to file a tax return | The tax office has information that you had income but did not file a return. | File the return within the deadline stated in the notice. |
| Notification of a tax audit | A formal audit of a specific tax for a specific year begins. | An amended return with a lower penalty can still be filed within 15 days. |
| Tax assessment decision | The audit has ended and the tax office has set the tax and the penalty. | Pay within 15 days to reduce the penalty, or consider an appeal within the deadline stated in the decision. |
| Fraudulent message in the office's name | An e-mail, text message or call asking for payment to an unknown account, login details or wallet recovery words. | Do not reply and verify directly with the office. |
Genuine documents from the Slovak tax administration arrive in the electronic mailbox on slovensko.sk, by registered post or in the personal internet zone on the tax administration portal. The tax administration never asks for a private key or wallet recovery words. More about scams that use leaked data is in the article on data leaks.
You received a notice: six steps
1. Check that it is genuine. Make sure it came through an official channel. If in doubt, call the tax office named in it, but use the number from the tax administration website, not from the letter.
2. Find out when you must reply. The deadline is stated in the notice and runs from delivery. With the electronic mailbox, a document is treated as delivered even if you do not open it, generally 15 days after it was deposited. Anyone who does not check the mailbox can miss the deadline without knowing about the letter.
3. Read exactly what is being asked. A notice usually concerns a specific year and a specific matter, for example income from selling crypto-assets in 2024 or transfers from an exchange to a bank account. Answer what is asked. If while preparing you find a mistake in another year as well, deal with it separately, ideally with an amended return for that year.
4. Gather the documents. The basis is transaction exports from every exchange you used, bank statements with deposits and withdrawals, a list of your own wallets and documents showing how you acquired the crypto. A detailed list follows below.
5. Recalculate. For every sale and every exchange you need the proceeds and the acquisition price. Where you bought the same crypto-asset several times at different prices, one consistent method is used, for example FIFO, meaning the first bought is the first sold, or a weighted average. The result has to be not only correct but also documented.
6. Reply in writing and on time. The reply should be factual: what you did, where, what the result was and which documents prove it. If you cannot meet the deadline, ask for an extension before it expires and give a reason. Silence is the worst answer. If a taxpayer does not cooperate, the tax office may determine the tax using estimation tools, meaning an estimate based on the data it has. It may not know an acquisition price that nobody documented.
What a reply can look like
A reply to a request for an explanation does not have to be long. What matters is that it is complete and that every statement is backed by a document. A proven structure looks like this:
| Part of the reply | What it contains |
|---|---|
| Introduction | whom you are replying to, the reference number of the document and the date it was delivered |
| Overview | which exchanges and wallets you used in the year concerned |
| Result | proceeds, acquisition price and gain or loss for the year, with the calculation method stated |
| Explanation of differences | why some transfers are not taxed, for example moves between your own wallets |
| Attachments | exchange exports, bank statements, calculation overview |
| Next step | if you found a mistake while preparing, a note that you are filing an amended return |
If a tax adviser prepares the reply, they submit it under a power of attorney and the tax office then communicates with them.
What not to do. Do not close exchange accounts before downloading the exports. Do not send the tax office estimates instead of figures you can document. And do not file an amended return in a hurry without recalculating. Every further amended return for the same year that raises the tax again means another penalty on the new difference.
Notification of a tax audit: fifteen days
A tax audit begins when the audit notification is delivered or a record of its start is drawn up. From that moment a fifteen-day period runs during which you can still file an amended return for the audited year. The penalty is then lower than if the auditor had found the difference. Once this period has passed, an amended return for the audited tax and year can no longer be filed and the tax office decides on the tax.
During the audit you have the right to submit evidence and comment on the findings. At the end you receive a report and can comment on it in writing. With crypto, disputes most often revolve around the acquisition price. Anyone who cannot document what they paid for their crypto risks having a larger part of the sale proceeds taxed than the actual gain.
How much a mistake costs depending on when you correct it
The Slovak Tax Procedure Code calculates the penalty from the missing tax for every day since the original filing deadline. The rate depends on the stage at which you correct the mistake. It is linked to the European Central Bank's main interest rate, which has been 2.65% since 16 September 2026. At that level the statutory minimums apply in all three cases.
| Situation | Statutory calculation | At today's ECB rate |
|---|---|---|
| Amended return on your own, before an audit begins | 1× ECB rate per year, at least 3% | 3% per year |
| Amended return within 15 days of the audit notification | 2× ECB rate per year, at least 7% | 7% per year |
| Difference found and assessed in an audit | 3× ECB rate per year, at least 10% | 10% per year |
When tax is assessed in an audit, since 2026 the penalty is reduced to two thirds if you pay the assessed tax within 15 days of receiving the decision. Even so, it remains higher than with an amended return filed on your own before an audit.
If you did not file a return at all. Many employees do not file a return because their employer does the annual settlement. Anyone who had taxable crypto income alongside their salary generally had to file a type B return themselves. A return filed late is subject to a penalty for not filing on time. For breaches until the end of 2025 the range is 30 to 16,000 euros, for breaches from 2026 it is 100 to 30,000 euros. On top of that comes late payment interest on the tax that was not paid on time. It is four times the ECB rate, at least 15% per year, and is charged for a maximum of four years. With a return that was never filed, a quick correction is therefore even more important than with an amended one.
Example: Peter and the year 2024
Peter is an employee and rents out a flat. For 2024 he therefore filed a type B return on time by 31 March 2025. He did not include his crypto income in it. In 2024 he sold bitcoin and ether with a gain of 8,000 euros, meaning sale proceeds minus acquisition price. For simplicity, assume his whole tax base stayed in the 19% band. The tax missing from the return is 1,520 euros.
| When Peter corrects the mistake | Rate | Penalty |
|---|---|---|
| On his own, with an amended return on 15 October 2026 | 3% per year | about €70 |
| With an amended return on 10 March 2028, nine days after receiving the audit notification | 7% per year | about €313 |
| Difference assessed in an audit, notification delivered 1 March 2028 | 10% per year | about €450 |
| The same, with the assessed tax paid within 15 days of the decision | two thirds | about €300 |
Peter pays the 1,520 euros of tax in every case. The difference lies in the penalty and in whether he deals with 2024 himself or an auditor does. In an audit the penalty runs until the 15th day after the audit notification is delivered. The figures are indicative. The exact penalty depends on the number of days and the ECB rate on the relevant day. In addition to the tax, Peter also pays health contributions on the same income, which the example does not include.
Amended return: when and how
When the obligation arises. If you find that the tax in a filed return should be higher, the Tax Procedure Code obliges you to file an amended return by the end of the month following the month in which you found out. If you find out in October, the deadline is the end of November.
How far back. The right to assess tax generally expires five years after the end of the year in which the return was due. The return for 2021 was due in 2022, so that year remains open until the end of 2027. Amended returns can therefore be filed for 2021 to 2025, and for 2020 the period expires at the end of 2026 at the earliest.
How it works. An amended return is filed on the form valid for the year concerned and shows the full correct amount, not just the difference. The tax difference is due within the deadline for filing the amended return. The tax office then imposes the penalty by decision. The health insurer also receives the return data and adjusts the annual contribution settlement accordingly.
If you made a loss. You can also file an amended return when the tax should be lower. In Slovakia, however, a crypto loss cannot be offset against salary or carried forward to later years. Within a single year, crypto gains and losses are netted against each other.
Situations most often overlooked with crypto
| Situation | How it is treated |
|---|---|
| Exchanging one crypto-asset for another | It is taxable even if you never saw a single euro. More in the article on crypto taxation in Slovakia. |
| Paying with a crypto-linked card | Every payment is a sale of crypto. See the article on crypto cards. |
| Transfer from an exchange to your own wallet | It is not a sale. In the DAC8 report, however, it appears as a transfer off the exchange, so you need to be able to explain it. |
| Crypto futures, perpetuals and options | These are derivatives with a different regime. See the articles on futures and options. |
| Account on an exchange that has left the EU | Trades are taxed the same way. Download the exports while the account is still accessible. Background is in the article on the end of the MiCA transition period. |
| Selling at a loss | The loss is only offset against crypto gains in the same year. |
What to prepare even if no notice has arrived
| Document | Where to find it | Why it matters |
|---|---|---|
| Transaction exports from every exchange | in the account settings, usually as a CSV file | the basis of the whole calculation |
| Exports from exchanges that have closed | download as soon as possible while the account is accessible | once an account is closed the data is hard to obtain |
| Bank statements | online banking | they link the exchange to the euros in your account |
| List of your own wallets | your own records | explains transfers off the exchange |
| Proof of acquisition | purchase confirmations, mining or staking statements | without them the acquisition price is hard to prove |
| Calculation overview for each year | a spreadsheet or software output | shows how you arrived at the figure in the return |
| Filed returns and filing confirmations | tax administration portal | what the tax office already has from you |
One rule applies: download your data now, not when a letter arrives. Exchanges change systems and close accounts, and deadlines for replying to the tax office tend to be short.
Short answers to common questions
Will the tax administration send me a notice automatically once it receives DAC8 data? Nobody knows that today. The law gives it the data, not an obligation to write to everyone. It is reasonable to assume that a mismatch between an exchange report and a tax return is a reason for a question.
Do I have to declare crypto I only hold? No. Sales, exchanges for another crypto-asset and payments with crypto are taxed. Simply holding crypto creates no tax liability.
I use a foreign exchange. Does this apply to me? Yes. A provider in another EU member state reports to its own tax administration, which sends the data to Slovakia by 30 September 2027. Many countries outside the EU are gradually joining the same OECD framework.
I received a request for an explanation. Can I still file an amended return with the lowest penalty? Yes. Until a tax audit has begun, the 3% per year rate applies to an amended return.
I have no documents for purchases made years ago. What can I do? Look for substitute evidence: bank statements with payments to the exchange, confirmation e-mails from the exchange, address history on the blockchain. The more independent traces, the better. An acquisition price you cannot document may not be accepted.
Key takeaways
The 2027 budget does not change tax rates, but it does not change the fact that the state needs money either. Since 2026 the tax administration also receives exchange data automatically. For an investor whose returns are correct, nothing changes. For anyone unsure about past years, now is the cheapest time to check. An amended return filed on your own costs a fraction of what the same difference costs when it is found in an audit.
If a notice arrives, there is no reason to panic, but no reason to delay either. Check that it is genuine, watch the deadline, prepare the documents and reply factually. With crypto, the most common weak point is documenting the acquisition price, and that can be prepared in advance.
This article is a general overview, not individual tax advice. With larger amounts, unpaid tax can also have a criminal law dimension, which this article does not cover. Recalculating trades for past years, preparing amended returns and replying to tax office notices are a regular part of the work kryptotax.sk does for clients.