FIFO vs. Specific Identification Accounting Methods

By default, the IRS, brokerage firms, and most trade accounting programs use the First-In- First-Out (FIFO) accounting method for securities. If you sell security A, its cost-basis is the first lot purchased — the first one “out” or sold. FIFO suits most active day traders.

But there is another option called the Specific Identification (SI) accounting method. Assume you bought several lots of security A over the year while the stock increased in price. You might prefer to use SI accounting instead of FIFO to specify a higher cost-basis lot to reduce your short-term capital gains for 2021. This enables you to hold the older purchased stock for 12 months at a lower cost-basis for a long-term capital gain taxed at a lower rate (up to 20% for 2021 and 2022).

The IRS requires contemporaneous action for using SI. You must specify the lot to sell before executing the sale, and the broker must confirm those instructions in writing at that same time. You cannot decide to use SI after the sale’s settlement date, like when preparing your tax returns. The IRS provides a little leeway to correct communication errors with the broker by allowing a settlement date rather than a trade date.

FIFO is also widely used for cryptocurrencies. While SI is the default accounting method for intangible property, it’s challenging to operate with cryptocurrencies. See Frequently Asked Questions on Virtual Currency Transactions | Internal Revenue Service (irs.gov)