Guide for calculating and paying capital gains tax when selling Bitcoin

In this blog post, we answer the most important questions about KeSt (capital gains tax) and use practical examples to explain what has happened when selling Bitcoin in Austria and therefore also at Coinfinity since January 2024, how much tax is withheld and whether you still have to enter the sale in your tax return.

Please consider the following important notes in connection with our disclaimer:

We've put a lot of effort into carefully creating this comprehensive guide for you. We also provide you with direct links to official sources wherever possible so that you can do further research yourself.

Please note, however, that we cannot be responsible for the timeliness or content of the information that we have provided to the best of our knowledge and belief.

This article is for informational purposes only and does not constitute tax, legal, or financial advice. It cannot replace a detailed and individual consultation with a tax expert. Coinfinity assumes no liability for the accuracy, timeliness and completeness of this contribution or for actions taken on the basis of the information in this article.

We are happy to help you, but as a company we need to be able to rely on the information you give us. You are responsible for their accuracy, so please check them carefully.


With the introduction of eco-social tax reform In March 2022, the then federal government decided to put Bitcoin at the same level as traditional capital assets in the area of capital gains tax (abbreviated “KeST”).

From 01.01.2024, Austrian Bitcoin brokers are required to withhold capital gains tax when selling cryptocurrencies purchased from 01.03.2021. This also applies to your sales of Bitcoin for euros via Coinfinity, provided that you have a main place of residence or habitual residence in Austria. In order to calculate capital gains tax correctly, we need information on acquisition dates and costs, which must then be checked by us for plausibility. The specific legislative text on this You can find it here.

This new development is an important step for the further spread of Bitcoin. However, it not only has advantages and can lead to questions, especially for those who do not regularly deal with Bitcoin.

As your reliable partner when it comes to Bitcoin, who is committed to providing the highest quality of service, we want to actively support you in this complex issue as best we can.

However, in order to be able to help you in the best possible way, we need some information from you. To do this, we will look at the following questions together:

1. What is the KeST anyway?

The KeST is the so-called capital gains tax. It is due to income from capital assets and the vast majority of us have actually paid bank accounts at least once in our lives.

Capital assets include various types of assets, including money in checking and savings accounts as well as investments in stocks, ETFs, funds and, more recently, cryptocurrencies such as Bitcoin. Capital Gains Tax (KeST) applies when you make a profit from these investments. This means if you receive interest on your savings account or current account, or if you sell stocks and Bitcoin at a higher price than you bought them. The bank account is 25% for checking and savings accounts and 27.5% for other forms of investment, such as stocks and Bitcoin. It is crucial to understand that capital gains tax (KeST) only applies to profits. For example, if you buy a Bitcoin for €100,000 and sell it for €110,000, the KeST only applies to the profit of €10,000. 27.5% (€2,750) of this is to be paid as tax. The remaining 7,250€ is “final taxed” for you and do not have to be stated in the tax adjustment.

If you bought a Bitcoin for €100,000 and, for whatever reason, sell it again for €90,000, you have made no profit. Therefore, there is no need to deliver a purchase order here.

Just like us, Austrian banks will automatically pay your bank account for you. That's why many people don't notice it at all in everyday life.

However, due to the requirements set by law, we need some information from you. We'll explain more about this in a minute.

2. I don't have Austrian citizenship at all, do I also have to pay KEST?

For the KeST, there is generally no question of which citizenship you have. Instead, the decisive factor is where you your tax residency You have. Basically, if you have your place of residence or habitual residence in Austria, are you unlimited taxable. A registered main place of residence is not absolutely necessary for this.

This means that all your income, both from Germany and abroad, is taxed in Austria.

If you are not subject to tax in Austria, we only need information about the country of your actual tax liability to enable you to sell Bitcoin without further inquiries.
However, if you are subject to tax in Austria, we need your tax number first. Your tax number always has the format XX/XXX/XXXX.
If you don't know how to get your tax number, there are the following three options after consultation with the tax office:

  • You can find your tax number in your Finanz online account
  • Your tax number is shown on every decision from the tax office (e.g. on your income tax adjustment)
  • You can find your tax number in direct contact received with the tax office

3. I don't want to pay a bank account, why don't I just sell my Bitcoin to a foreign provider?

Some may be considering selling their Bitcoin to non-Austrian providers in the hope of evading capital gains tax (KeST). But even if these providers do not directly deduct the tax liability in Austria. Put simply: You must pay the same amount to the Austrian tax office, but you are on your own during this process.

In order to avoid such complicated situations, we offer you our comprehensive support. Of course, you can also sell Bitcoin on Coinfinity, even if you bought it on other platforms — and at no additional cost.

4. What do I do if my Bitcoin is with a service provider who does not pay the capital gains tax (KeST) for me?

In that case, you have two options.

  • On the one hand, you have the opportunity to sell your Bitcoin with us and take advantage of our free KeST service.
  • Alternatively, you can continue selling your Bitcoin through your previous provider. However, it is your responsibility to collect all necessary information yourself and to ensure that it is fully and timely detailed in your annual income tax return. Note that incomplete or late information may lead to consequences under financial criminal law.

5. Which Bitcoin does KeST actually affect?

Within the framework of the CEST, the legislator distinguishes between a so-called”Old stock“and a so-called”new stock”.

As Old stock The legislator defines all Bitcoin that was purchased before 01.03.2021. These are exempt from the tax exchange rate, meaning that winnings remain with you in full. Nevertheless, due to legal requirements, we need information on the time of purchase and the acquisition costs, even if the inventory is old.

As new stock All Bitcoins purchased from 01.03.2021 apply. These are fully subject to KEST. Here, too, we need information about the time of purchase and the acquisition costs for processing.

6. Which Bitcoin am I selling anyway?

The legislator allows you to freely decide which Bitcoin you want to sell. So you can definitely sell Bitcoin that falls into the new inventory before Bitcoin that falls into the old inventory. See also the text on Cryptocurrency regulation.

Since we always ask you which Bitcoin you want to sell, Coinfinity always gives you exactly the solution that you want.

7. What do I do if I have both old and new Bitcoin assets in the same wallet?

Since old stocks and new stocks are valued differently for tax purposes, they cannot be sold in the same step. So that no confusion can arise here, we will specifically ask you about this at the beginning of the sales process.

Mittelherkunft trennen

Please clearly separate your Bitcoin from each other in advance and then let us know the desired values.

8. What do I do if I have distributed my Bitcoin across multiple wallets?

Of course, you can sell Bitcoin from all common wallets with us. However, please note that for technical reasons, only Bitcoin can be sold from one wallet per sales step.

If you want to sell Bitcoin from different wallets, you can simply start a separate sale for each wallet.

9. I want to enter my average purchase cost, but I get an error message.

For your safety, we automatically check the plausibility of your reported acquisition costs compared to the historical exchange rates in the background.

If the reported acquisition costs are unrealistic, for example, you specify an acquisition cost of €1,000 for an entire Bitcoin in 2023, our plausibility check will fail and you will receive an error message.

Anschaffungskosten nicht plausibel

In this case, please check your input for possible errors or even typos so that your KEST information can also be entered correctly.

10. What do I do if I no longer know when or at what initial cost I bought my Bitcoin?

In the event that it is no longer possible for you to specify when or at what acquisition cost you bought your Bitcoin after 01.03.2021, the legislator has also created a solution.

To do this, do not include old inventory or new inventory in the sales process, but”Unknown” on. In this case, it is still possible to sell your Bitcoin.

In such cases, the legislator automatically sets 50% of the sales revenue as fictitious acquisition costs. The remaining amount is subject to capital gains tax (KEst). For example, if you sell €100,000 worth of Bitcoin under “Unknown,” €50,000 is counted as fictitious acquisition costs. The remaining €50,000 is your fictitious profit, which is taxable at 27.5% KEST, which corresponds to a tax of €13,750.

Important: In contrast to old inventory and new inventory, the tax under “unknown” applies legally not taxed as final. You must therefore report this sale in your income tax return. This means that this option should only be considered as a last resort.

11. What information do I need so that Coinfinity can process the KeST for me?

You must tell us the purchase period and the average purchase costs. To repeat: The KeST only applies to “new inventory”. For all Bitcoin purchased before 01.03.2021, this is not relevant. To do this, simply select the “Existing Inventory” option at the beginning of the sales process for this Bitcoin. Although we are required to check the purchase date and the purchase costs, they still remain KEST exempt.

12. How do I calculate the average purchase cost when selling new inventory?

In the case of several purchases in chronological order and storage on the same Bitcoin address or wallet, the legislator requires the use of the moving average price (“GLD”) method, see Section 2 of the Cryptocurrency regulation. Here you can find the Definition of GLD on Wikipedia.

It is a calculation method that determines the average price of your Bitcoin, taking into account purchases and sales over a specific period of time. The GLD is only relevant for new inventory.

The average purchase costs are derived from this formula:

Average purchase costs = Number of BTC to sell x GLD

In order to calculate the GLD correctly, you must look at the history of your Bitcoin address or wallet, taking into account all purchases and sales of the new inventory. Any existing inventory is not taken into account, but should be considered separately from it.

The GLD is recalculated with every purchase. This formula applies to this:
GLDnew = ( GldAlt  x inventory  + Purchase quantity x Shopping course )/ inventory

Note that when you sell, the GLD remains the same and does not change. When sold, only the total Bitcoin inventory changes.

Fictitious example calculation

Here is a fictional example to illustrate. In this example, Bitcoin was bought and sold several times between 10.01.2023 and 30.08.2023. It is therefore a new inventory.

The GLD is recalculated after each purchase; when selling, the GLD remains the same; only the inventory quantity changes.

Berechnung mit Beispiel

In this fictitious example, if we want to sell the amount of 0.5 BTC on 31.08.2023, then we proceed as follows:

Average purchase costs = 0.5 BTC x 25.172 EUR = 12.586 EUR

In this example, the average purchase cost for selling 0.5 BTC is 12.586 EUR.

For a sale in our example, we first select “new inventory”:


In the second step, we enter the amount of Bitcoin to sell (0.5):


In the third step, we enter the wallet's consideration period, i.e. from 10.01.2023 to 30.08.2023:


In the fourth step, we give the previously calculated value of 12.586 EUR as the acquisition cost:

Berechnung KESt

13. How do I calculate the purchase costs when selling old inventory?

If you want to sell Bitcoin from pure old inventory, there is no capital gains tax. Nevertheless, you must announce the purchase period and the purchase costs during the sales process.

Unlike new inventory, you don't have to use the moving average price for the purchase costs, but can specify the actual purchase price of Bitcoin.

14. Can I include fees in the purchase costs?

Yes, fees (such as the service fee charged by Coinfinity) can be added to the purchase costs as ancillary acquisition costs.