If the exchange has closed, you prove origin by combining what you kept (emails, exports, screenshots, bank transfers to and from the exchange) with blockchain evidence of withdrawals from the exchange's known wallets to your own addresses. Where the exchange went through insolvency, the liquidator or trustee often holds account data and may provide statements or claim records. A report then ties these pieces together and states clearly which steps are proven and which are only corroborated.
Start with what you already have
Most people hold more evidence than they think. Collect everything before contacting anyone:
- Bank statements with transfers to and from the exchange.
- Emails: account opening, identity verification, deposit and withdrawal confirmations, monthly statements.
- CSV exports, PDF statements or screenshots you saved at the time.
- Tax returns or accountant files where the exchange balance was reported.
- The addresses you withdrew to, from your wallet software or hardware wallet.
Ask official sources
If the exchange is in bankruptcy or liquidation, the administrator usually runs a claims process and holds the customer database. Your filed claim, the balance recognised and any distributions received are strong documents in themselves. If the exchange was acquired or wound down voluntarily, the successor company or the former operator may still answer a personal data access request under the GDPR or similar laws.
Use the blockchain to fill gaps
Exchanges move customer withdrawals from wallets that analytics providers have identified and labelled. Matching the amounts and dates of your withdrawals with transactions from those wallets to your addresses shows that the coins left that exchange to you. Combined with the fiat transfers into the exchange from your bank, this often closes the circle even without a full account history.
Exchange attribution is not always complete, especially for small or regional platforms. In those cases the report explains which wallets were linked to the exchange and on what basis, so the bank can weigh the evidence itself.
When evidence is partial
Banks do not expect perfection, they expect coherence. A report that shows the fiat going in, the coins coming out, a consistent timeline and declared tax positions is often sufficient, provided missing elements are named rather than hidden. The bank still decides on its own risk appetite.
How Advisorn helps
Advisorn matches your records with labelled exchange wallets and signs a report with the annexes a bank can check. We also handle requests to administrators where useful and answer the bank's follow-up questions.
EU General Data Protection Regulation (GDPR) art. 15 (right of access), as an example of data access rights
Updated November 2026 · General information, not legal or tax advice on your specific case.