Hard Forks, Airdrops, and Token Splits: Cost Basis Treatment

Hard forks and airdrops generate tokens you didn’t buy — and immediately raise the question of whether you owe tax and, if so, what your cost basis is. Rev. Rul. 2019-24 answered part of the question. Here is how Saim Akif, CPA applies it to the full range of fork and airdrop scenarios in client filings.

Rev. Rul. 2019-24: The Governing Framework

Rev. Rul. 2019-24 addressed two scenarios:

• Hard fork without airdrop: A hard fork occurs (e.g., a blockchain splits), but the taxpayer receives no new tokens — only the existing token on the new chain. No income is recognized. The original basis carries over.
• Hard fork followed by an airdrop: The taxpayer receives new tokens as a result of the fork/airdrop. The ruling holds that the taxpayer has ordinary income equal to the FMV of the received tokens at the moment they obtain “dominion and control.”

Dominion and control is established when you can “sell, exchange, or otherwise dispose of” the new tokens. If the token exists on-chain at a wallet you control, you generally have dominion and control — even if you haven’t moved or sold it yet.

“Rev. Rul. 2019-24 settled the hard fork issue but left ambiguity on timing — particularly for tokens received at an illiquid market or before any exchange listing. We document the FMV methodology carefully for every airdrop.”

— Saim Akif, CPA

FMV at Receipt: The Valuation Challenge

For major forks (Bitcoin Cash from Bitcoin in 2017, Ethereum Classic, etc.), exchange-listed prices are available at or near the fork date, making FMV determination straightforward. For obscure airdrops of newly created tokens:

• If the token has no market at receipt (not yet listed), a reasonable argument exists that FMV is zero — no income recognized until the token becomes marketable and is sold.
• If the token has a listed price at receipt (even briefly on a DEX), the IRS will likely treat that price as FMV. Document the price source and timestamp.
• For retroactive airdrops (tokens distributed months after a snapshot), the income recognition date is the date of actual receipt, not the snapshot date.

Basis = FMV at Receipt

Once income is recognized, your cost basis in the new tokens equals the FMV at which income was recognized. This basis is used to calculate gain or loss on any subsequent sale. If you recognized $0 of income at receipt (because the token was illiquid), your basis is $0 — meaning a future sale generates 100% gain.

Common basis mistakes in fork/airdrop situations:

• Treating the entire proceeds of airdrop token sales as capital gain, without recognizing the portion that was ordinary income at receipt (double benefit; the IRS matches 1099s for large token liquidations)
• Using the snapshot date FMV instead of the receipt date FMV for retroactive airdrops
• Failing to track the basis of the original pre-fork token (which may need to be allocated between the old and new tokens if the fork results in both chains continuing)

Hard Fork Without Airdrop: Original Basis Carries Over

When a blockchain forks and no new tokens are distributed (for example, a contentious fork where the old chain continues and is simply renamed), the original basis in the pre-fork tokens carries over entirely to the post-fork tokens. No income is recognized, and the holding period continues uninterrupted. This scenario is uncommon but occurs with rebranding events and certain protocol upgrades.

Recordkeeping Templates

For every airdrop or fork event, Saim’s practice captures:

• Token name and contract address
• Date of snapshot (if applicable) and date of receipt on-chain
• Number of tokens received
• FMV per token at receipt (source: CoinMarketCap, CoinGecko, or DEX price at timestamp)
• Ordinary income recognized (tokens × FMV)
• Cost basis established (same as ordinary income recognized)
• Exchange or wallet where received

This template becomes part of the Form 8949 cost basis documentation and is retained in the client file for audit purposes. See our 1099-DA Hub for how airdrop income integrates with 1099-DA reporting starting in 2025.

Need Help?

Fork and airdrop tax treatment is one of the most documentation-intensive areas of crypto tax. Saim Akif, CPA builds the FMV analysis and basis records for every fork and airdrop in your transaction history. Schedule a 30-minute intake with Saim.