Why is the IRS so interested in cryptocurrency anyway?

The short answer is money. The IRS believes a large amount of crypto gain has gone unreported, and it has spent years building the tools to find it. Crypto is not a loophole to the agency. It is property, the same as a share of stock or a rental house, and gains on property are taxable. When a lot of people stopped reporting those gains, the IRS treated it as a collection problem and went to work.

How wide the gap actually was

The early numbers were stark. For the 2015 filing year, fewer than 1,000 taxpayers reported crypto gains or losses to the IRS, while millions of Americans were already trading. In 2018, one tax-filing service reported that only about 0.04% of its users had entered any crypto activity at all. Coinbase alone had millions of U.S. account holders by then. A gap that wide is exactly the kind of thing the IRS is built to close.

Where the IRS gets its information

The agency does not have to guess anymore. It subpoenaed customer records from exchanges years ago, and the enforced Coinbase summons in 2017 is the best known example. It now also receives routine reporting from brokers. For sales made in 2025 and later, U.S. custodial exchanges send both you and the IRS Form 1099-DA, which reports the gross proceeds from your digital-asset sales. Cost-basis reporting on that form phases in for 2026 activity. Form 1040 also asks a plain yes or no question about digital assets near the top of the return, so answering it is not something you can skip.

There is a catch worth understanding. Gross proceeds are not the same as your gain. A 1099-DA, or the older 1099-K that some platforms still send, can show a large total of what you sold without showing what you paid for it. If the IRS sees the proceeds but not your cost basis, the figure it starts from will look far bigger than what you actually owe. If you bought at $9,000 and sold at $10,000, an unadjusted record can read as if the whole $10,000 was profit.

The letters the IRS sends

Back in 2019 the IRS mailed more than 10,000 letters to crypto holders, and it still sends the same types today. Which one lands in your mailbox tells you how much attention you are getting. Find the number first, usually in a corner of the notice.

The CP2000 is the one that looks scariest, because it names a dollar figure. That figure is often too high for the same reason above: the IRS saw your proceeds from an exchange without your basis. Showing your basis, sale by sale, is how the number comes down.

What to do if one arrives

1. Find the number. 6174, 6174-A, 6173, or CP2000. It sets everything that follows.
2. Note any deadline. A 6173 and a CP2000 both carry a response date. Missing it is the real risk.
3. Pull your records. Exchange exports and wallet history for the years the letter names.
4. Rebuild your basis. This is what turns an inflated proceeds number into your actual gain.
5. Correct it on your own terms. An amended return you file yourself is a far better position than an audit that finds the gap for you.

Why "any tax preparer can do this" is a trap

Crypto is a narrow specialty, and being good at ordinary returns does not mean someone can handle wallets, transfers between exchanges, staking rewards, or DeFi. A few years ago a major consumer tax product told users they could file crypto with a 1099-K, which does not work. The rules keep moving too. Revenue Ruling 2019-24 set out how hard forks and airdrops are taxed, and the 1099-DA reporting regime is new for the 2025 tax year. If you want to test a preparer, ask two questions. Can I file my crypto with a 1099-K? The answer is no. How is crypto taxed? The answer is as property. A wrong or vague reply is your signal to keep looking.

The IRS is not going to lose interest in crypto. The volume of data it receives grows every year. If you are in its sights, the worst move is silence. A letter is answerable, and almost every bad outcome here comes from ignoring one, not from the crypto itself.