Cryptocurrency is a type of virtual currency that uses cryptography to secure transactions that are digitally recorded on a distributed ledger, such as a blockchain. A transaction involving cryptocurrency that is recorded on a distributed ledger is referred to as an “on-chain” transaction; a transaction that is not recorded on the distributed ledger is referred to as an “off-chain” transaction.

You may identify a specific unit of virtual currency either by documenting the specific unit’s unique digital identifier such as a private key, public key, and address, or by records showing the transaction information for all units of a specific virtual currency, such as Bitcoin, held in a single account, wallet, or address. This information must show (1) the date and time each unit was acquired, (2) your basis and the fair market value of each unit at the time it was acquired, (3) the date and time each unit was sold, exchanged, or otherwise disposed of, and (4) the fair market value of each unit when sold, exchanged, or disposed of, and the amount of money or the value of property received for each unit.

The Internal Revenue Code and regulations require taxpayers to maintain records that are sufficient to establish the positions taken on tax returns. You should therefore maintain, for example, records documenting receipts, sales, exchanges, or other dispositions of virtual currency and the fair market value of the virtual currency.