Did the coinbase lock move your XBT tax date?

XBT mining rewards now sit locked for about 180 days before they can move. If you mine XBT in the US, that raises a real question: is the reward income on the day it's mined, or on the day it unlocks? The IRS hasn't said. Here are the two readings, what each means for your 2026 and 2027 returns, and what to write down now.

Not tax advice. US federal rules only. Talk to a tax professional who knows crypto before you file.

The lock, in one paragraph

Every block reward from block 979,919 (Oct 31, 2026) on is locked for 25,920 blocks, about 180 days, under the rule Bitcoin Knots 29.4.3 enforces. Rewards from the earlier 45-day window unlocked at block 979,920, and Knots relay policy releases them about 45 days after each was mined, through mid-December. So a reward mined today, Nov 2, 2026, can't move until around May 1, 2027. How the lock hits pool payouts.

What the IRS has said

• Mining: IRS Notice 2014-21 says mined coins are income at their fair market value "as of the date of receipt."
• Staking: Rev. Rul. 2023-14 says rewards are income when you gain "dominion and control" over them, meaning you can sell, exchange or otherwise dispose of them.
• Locked coinbase rewards: nothing. No guidance covers a reward that consensus rules won't let anyone spend for six months.

Reading 1: income when it's mined

The older, simpler reading. The block is found, the reward is "received," and it's income at that day's price, even though you can't touch it. A reward mined in November or December 2026 is 2026 income.

Reading 2: income when it unlocks

The dominion-and-control reading. A coin nobody can spend isn't really in your control, so the income lands on the unlock day, at that day's price. A reward mined from Oct 31, 2026 on would be 2027 income. The BLAKE2b Miner blog laid this out last week, with a line worth keeping: "A year locked is not a year held." blog.blake2bminer.com

Same reward, different tax

One full block reward of 3.125 XBT, mined today at about $358. Under reading 1, that's about $1,119 of 2026 income. Under reading 2, it depends on the price around May 1, 2027:

Pool miners get a slice of each reward, but the math scales the same way.

The holding-period catch

Long-term capital gains rates need more than a year of holding. Under reading 2, the clock starts at unlock, and your cost basis is the unlock-day value. The six locked months don't count. A reward mined in November 2026 that unlocks in May 2027 isn't long-term until about May 2028.

The thin-market trap

Either way, the income is set by a price, not by what you can actually sell for. XBT trades about $1M a day across a handful of markets. If a lot of rewards unlock into a thin book, the price you're taxed on and the price you can get may not match. Some miners set aside a tax reserve against the income value, not against a hoped-for sale.

If you're paid by a pool

Many pool miners never hold a locked coinbase output at all. The pool holds it and pays you later, or pays you early from its own funds. In that case you received XBT you can move on the day the pool paid you, and that's the date most people would use. Ask your pool how it pays under the lock and keep its payout records.

What to write down now

• Block height and date for each reward or pool payout
• The unlock height and date for any locked reward you hold yourself
• The XBT price on both dates, from one consistent source
• When and for how much you sell

xbt.live publishes one unrevised USD reference price per day for this: daily reference price. The XBT tax helper turns a list of rewards into fair market values with a Koinly or CoinTracker export.

XBT tax helperUnlock tracker

Sources: IRS Notice 2014-21; Rev. Rul. 2023-14; Bitcoin Knots 29.4.3 release notes; xbt.live lock tracker. Prices from xbt.live, Nov 2, 2026. xbt.live is not a tax adviser, and nothing here is tax, legal or financial advice. Rules outside the US differ.

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