How to import Bolero into Cryptotax

How to import Bolero into Cryptotax

Bolero (KBC) does not offer an export of your transactions. That is why Cryptotax made a small export script. You paste it into your own browser while you are logged in to Bolero. The script reads your full transaction history and downloads it as one CSV file, which you then upload to Cryptotax. You do not need an API key and you share your Bolero login with no one.

What you need

• An account on Bolero
• An account on Cryptotax (see create account)
• A computer with Chrome, Edge or Firefox. It does not work on a phone or tablet, because they have no console.

Step 1: Log in to Bolero

1. Open platform.bolero.be on your computer and log in as usual, for example with itsme.
2. Keep that tab open.

Step 2: Copy the script

1. Log in to Cryptotax, go to Wallets and choose Add.
2. Pick Bolero from the list of sources.
3. Click Copy the script. Want to read what it does first? Click View the script, or open cryptotax.be/downloads/bolero-export.js.

Step 3: Run the script in your Bolero tab

1. Go back to your Bolero tab.
2. Open the console: press F12 (on a Mac Cmd + Option + J in Chrome or Edge, Cmd + Option + K in Firefox) and choose the Console tab.
3. Paste the script and press Enter. The first time, your browser asks you to type allow pasting first. That is a normal safeguard: type it, press Enter and paste the script again.
4. Wait for the message Downloaded bolero-cryptotax-...csv. With a long history this takes about a minute.

The file is now in your Downloads folder, with a name like bolero-cryptotax-1234567-2026-11-01.csv.

Step 4: Upload the file in Cryptotax

1. Drag the CSV file into the upload field on the Bolero screen in Cryptotax, or select it with the file picker.
2. Confirm the upload. Cryptotax processes your history and calculates your results.

What exactly does the script do?

• It runs only in your own browser and uses your own, existing Bolero session.
• It only reads data: your transaction history, the details of each transaction (quantity, price, costs and stock exchange tax) and the ISIN code of each security. It places no orders and changes nothing on your account.
• It only talks to Bolero itself (api.bolero.be). Nothing goes to Cryptotax or anyone else. The file stays on your computer until you upload it yourself.
• The code is public and readable, so you or someone you trust can check what it does.

Important notes

• Crypto and securities: crypto, ETFs and shares you bought or sold through Bolero count in your capital gains calculation. For ETFs and shares, FIFO applies per securities account, the last 2025 closing price is the value on 31/12/2025, and fees and stock exchange tax do not count. The value on 31/12/2025 comes from our list of closing prices for common ETFs. If your security is not on it, we use your purchase price and show a notice for you to check. It remains an indicative calculation. Together with your crypto they fall under one shared exemption of 10,000 euros. How Cryptotax applies one exemption (Dutch).
• Not supported yet: dividends, corporate actions (such as splits), security transfers and options are not included by the script yet.
• Belgian broker: Bolero is a Belgian broker of KBC. Cryptotax therefore does not treat your Bolero account as a foreign account.
• New transactions? Run the script again later. It reads your full history every time.

Troubleshooting

• "No Bolero session found": you are not (or no longer) logged in in that tab. Log in again, open Orders once and paste the script again.
• "Bolero session expired": your session expired while reading. Log in again and run the script once more.
• Nothing happens after pasting: check that you are in the Console tab and not another developer tools tab, and that you typed allow pasting first.
• The script does not run on another site: it only works on platform.bolero.be. Paste it in your Bolero tab, not in the Cryptotax tab.
• The file is rejected: upload the CSV file exactly as the script downloaded it, without opening and re-saving it in a spreadsheet.

Related articles

• Importing transactions via CSV
• How to connect your first exchange