How to prepare your transaction history for a crypto analysis

You may have bought crypto on several exchanges, changed wallets, or kept exports in different folders. Before your transactions can be analysed, you need to know which information is available and which periods it covers.

This preparation is useful to a private individual in Belgium approaching tax calculations, or documenting the path of funds for a bank. Here is a method for gathering the documents and flagging the questions to examine.

1. Take an inventory of your accounts and wallets

Start with a simple list. For each exchange or wallet, note its name, the period you used it and the documents you hold. Add the accounts you closed or stopped using.

For a wallet, record the networks used and the relevant public addresses. Give each source a name you will recognise later, such as "main wallet" or "old exchange account". You will then be able to explain what each file corresponds to.

You do not need to find everything before getting in touch. An inventory that states its gaps clearly is already a starting point.

2. Export the histories that are available

Use the export function on each exchange and keep the downloaded files in their original format. Note the period you selected and check whether several exports are needed to cover your activity.

The documents on offer do not always contain the same information. Kraken separates, among other things, trades, account movements covering deposits, withdrawals and fees, and balances on a given date. See its official guide to exporting your account history to choose the documents that match your inventory.

Check the scope of each tool as well. Coinbase states that Coinbase Taxes covers Coinbase.com activity and does not include Coinbase Wallet or Coinbase Pro transactions. A report from one exchange is therefore no substitute for your inventory of every source you used. See Coinbase's official help page on the reports available.

3. Add the documents that explain the movements

Gather the supporting documents you have for movements between your bank, the exchanges and your wallets. Depending on your history, these may be transaction confirmations, statements or transaction references.

For movements you recognise between your own accounts, note the source and the destination as you know them. Where a match is uncertain, mark it "to be checked". That note helps prepare the analysis without settling how the transaction should be treated.

Describe the unusual events that an export does not make obvious: a move from one exchange to another, an account migration, or an asset that changed name. Attach whatever documents you kept about them.

4. File the documents without altering the originals

Create one folder per source, then per period if needed. A name such as Exchange_HistoryType_2024-01_2024-12.csv makes a document quick to find. Keep the original copy and work on a separate copy if you want to add comments.

Prepare a short index with four columns: source, period, file and remark. For example: "old exchange; January to June 2023; export available; July to December missing".

Avoid replacing exports with screenshots when the source file exists. Keep screenshots as a supplement, for information that does not appear in the downloaded documents.

5. Flag what is missing and protect your access

Do not reconstruct a transaction from memory as though it were confirmed. Separate the documents you found, what you remember and the questions still open. A precise list of the gaps makes it easier to decide which searches to run next.

Never put your recovery phrase in the file. Ledger repeats that it must stay private and must not be shared with anyone, in its official article on scam attempts (in French). Passwords and login codes have no place among your supporting documents. Before sending personal documents, agree the channel with the person you are dealing with.

Your checklist

• The exchanges and wallets you used are listed.

• The periods covered by each export are identified.

• The original files are kept.

• The available supporting documents and useful references are in one place.

• The missing periods and the uncertain matches are flagged.

• No password, login code or recovery phrase appears in the file.

Are you now preparing calculations or a discussion with your bank? See our crypto tax support service and our crypto-to-bank support service.

To take stock of your documents and the next steps, book a first 30-minute video call, free and with no obligation.

Sources consulted on 16 September 2026: Kraken, Coinbase and Ledger, each linked next to the relevant passage.