Resolving a long-standing question, the guidance says new cryptocurrencies created from a fork of an existing blockchain should be treated as an ordinary income equal to the fair market value of the new cryptocurrency when it is received.

In other words, tax liabilities will apply when the new cryptocurrencies are recorded on a blockchain if a taxpayer actually has control over the coins and can spend them.

A23. When you receive cryptocurrency from an airdrop following a hard fork, you will have ordinary income equal to the fair market value of the new cryptocurrency when it is received, which is when the transaction is recorded on the distributed ledger, provided you have dominion and control over the cryptocurrency so that you can transfer, sell, exchange, or otherwise dispose of the cryptocurrency.

A24. If you receive cryptocurrency from an airdrop following a hard fork [] You have received the cryptocurrency when you can transfer, sell, exchange, or otherwise dispose of it, which is generally the date and time the airdrop is recorded on the distributed ledger.