I'm surprised this hasn't made it on the forum when it was posted on Reddit in Feb.

IRS Crypto tax AUDIT notice probes deep - original Reddit thread

Quote

Provide the following for all virtual currency transactions during the time period 01/01/2017-12/31/2017

Detailed records for the acquisition and disposition of any virtual currency (domestic or international), including but not limited to:
- Emails, screen prints, hardcopy prints, and transaction receipts maintained by the taxpayer or provided by any third-party such as an exchange, broker, or peer-to-peer facilitator (e.g. Paxful, Localbitcoins.com)
- Wire transfer or direct deposit records, including automated clearing house (ACH) and electronic funds transfer (EFT) records.
- List of all virtual currency kiosk (i.e., BTM or cryptocurrency kiosk or ATM) locations used along with copies of any transaction receipts or acknowledgements whether provided electronically or in paper.
- A detailed list of cryptocurrency transactions involving cash including dates, input/output counterparties involved in the transaction, and the cryptocurrency involved
- All correspondence (I.e., emails, texts, tweets, etc.) with all counterparties to any virtual currency transactions
- List of all virtual currency received from hard forks, faucets, tipping, or any other method where a sale, buy, or exchange was not initiated by the receiver of cryptocurrency (commonly called airdrops), including date, type, and amount of virtual currency received with the date of sale, or other disposition, including amounts and description of what was received
- Explanation of the method used to compute basis relating to the sale or other disposition of virtual currency
- Records reflecting the valuation of any sale or other disposition of virtual currency at the time of acquisition and disposition
Records relating to any expenses paid or items purchased (whether domestic or international) using virtual currency
List of all blockchain addresses owned or controlled by taxpayer
Records of all transactions relating to lending of virtual currency or use of virtual currency as collateral for loan, including, but not limited to, loan agreements, promissory notes, ledgers, transaction receipts, pledge, security, or collateralization agreements
List of all digital currency exchanges (DCE) and peer-to-peer (P2P) facilitators (e.g., Coinbase, Paxful or Localbitcoins.com) (foreign and domestic) with associated user Ids, email addresses, IP addresses, and account numbers relating to those platforms
List of all counterparties for any P2P virtual currency transactions (identifying the on-chain and off-chain transactions), email address, user IDs transactions.

This is not an all-inclusive list. Requests for additional information may be made if considered necessary.