Sources checked 10 November 2026. This page is education for companies that hold, or are considering holding, bitcoin. It explains the subsidy schedule, what people mean by a four-year cycle, and what a halving does and does not change for a company. It is not a forecast of price, miner revenue or network security, and it is not advice to buy, sell or hold.
Short answer
A halving is a scheduled cut in the new bitcoin paid to whoever produces a block. It happens every 210,000 blocks under rules in Bitcoin Core. Coins a company already holds are unchanged. Wallets, books and tax do not need to be rewritten because the date is approaching. Halvings attract headlines and claims about a repeating four-year price cycle. Those claims rest on a very small sample and sit alongside many other market drivers. A written treasury policy, with sizing and rebalancing rules set in advance, is the useful response, not a reaction to the news.
What a halving is
Each block can pay its miner a block subsidy of newly created bitcoin, plus the fees of the transactions it includes. Bitcoin Core's GetBlockSubsidy function starts that subsidy at 50 BTC and halves it every 210,000 blocks, by integer right shift, until 64 halvings have occurred and the subsidy is zero. The comment in that function describes the interval as approximately every four years, because the network targets one block every 10 minutes. The date of any future halving is still only an estimate, because real block times vary.
Source: Bitcoin Core: src/validation.cpp: GetBlockSubsidy, 50 BTC halved every 210,000 blocks, Bitcoin Core: src/kernel/chainparams.cpp: halving interval of 210,000 blocks, 10 minute block target, two week retarget, genesis block.
The subsidy eras and the four halvings so far, with dates taken from the block timestamps on mempool.space, are:
| Event | Block | Date (UTC) | Subsidy after |
|---|---|---|---|
| Start of issuance | 0 | 3 January 2009 | 50 BTC |
| First halving | 210,000 | 28 November 2012 | 25 BTC |
| Second halving | 420,000 | 9 July 2016 | 12.5 BTC |
| Third halving | 630,000 | 11 May 2020 | 6.25 BTC |
| Fourth halving | 840,000 | 20 April 2024 | 3.125 BTC |
| Fifth (next) | 1,050,000 | Estimate only, see below | 1.5625 BTC |
Source: mempool.space: Block 0, the genesis block (3 January 2009), mempool.space: Block 210,000, the first halving (28 November 2012), mempool.space: Block 420,000, the second halving (9 July 2016), mempool.space: Block 630,000, the third halving (11 May 2020), mempool.space: Block 840,000, the fourth halving (20 April 2024).
Each completed era of 210,000 blocks issues 210,000 times that era's subsidy: 10,500,000 BTC in the first era, then 5,250,000, 2,625,000 and 1,312,500. By the last 6.25 BTC block (height 839,999), 19,687,500 BTC had been created by the subsidy schedule. That is 93.75% of the 21 million cap in MAX_MONEY. The current era, at 3.125 BTC per block, can issue at most another 656,250 BTC. After the next halving the era cap falls to 328,125 BTC. Later cuts are smaller still in absolute terms. Total issuance approaches, but never quite reaches, 21 million, because the subsidy is rounded down to whole satoshis.
Source: Bitcoin Core: src/validation.cpp: GetBlockSubsidy, 50 BTC halved every 210,000 blocks, Bitcoin Core: src/consensus/amount.h: COIN (100,000,000 satoshis) and MAX_MONEY (21 million BTC), Bitcoin BIPs: BIP 42: A finite monetary supply for Bitcoin.
Next halving: block 1,050,000
Around April 2028
About 74,719 blocks to go at block 975,281 (checked 10 November 2026).
This is an estimate, not a fixed date. It assumes one block every 10 minutes on average, the same method as the bitcoin calendar. Real block times vary, so the actual month can move. The subsidy will fall from 3.125 BTC to 1.5625 BTC. The figure updates from mempool.space when the page loads. If scripts are blocked, the fallback above is the height checked on 10 November 2026, when mempool.space and Blockstream both reported 975,281.
Source: mempool.space: Chain tip height, 975,281 (checked 10 November 2026), Blockstream Esplora: Chain tip height, 975,281, agreeing with mempool.space (checked 10 November 2026), mempool.space: REST API documentation: block height, hash rate, difficulty adjustment and fee estimates.
What it does to the network
Miner revenue
A miner's block reward is the subsidy plus the fees in that block. Bitcoin Core enforces this: the coinbase may not pay more than nFees + GetBlockSubsidy. After a halving, the subsidy half of that sum drops overnight. Fee income does not automatically rise to fill the gap. It depends on demand for block space, which varies.
Source: Bitcoin Core: src/validation.cpp: GetBlockSubsidy, 50 BTC halved every 210,000 blocks, Bitcoin developer documentation: Mining: proof of work, difficulty and the block reward.
A snapshot, not a forecast, shows how small the fee share can be in a quiet window. Over the 144 blocks ending at height 975,281 on 10 November 2026, mempool.space reported total miner revenue of 45,304,040,778 satoshis, of which 304,040,778 satoshis were fees. That is about 0.67% of revenue. The rest is exactly 144 times the 3.125 BTC subsidy (450 BTC). Over the 2,016 blocks ending at the same height, a full difficulty period, fees were 4,059,341,615 satoshis of 634,059,341,615 satoshis of revenue, about 0.64%. Those two windows are similar. They are not a typical rate for every period, and they say nothing about a future era.
Source: mempool.space: Mining reward stats for the 144 blocks ending at 975,281 (checked 10 November 2026), mempool.space: Mining reward stats for the 2,016 blocks ending at 975,281 (checked 10 November 2026).
Hash rate and difficulty
The network targets one block every 10 minutes. Every 2,016 blocks, which is nPowTargetTimespan (14 days) divided by nPowTargetSpacing (10 minutes), difficulty resets up or down so that the average stays close to that target if hash rate has changed. If some miners switch off because the subsidy has halved and their costs are no longer covered, the remaining miners do not keep producing slower blocks for long: the next retarget makes valid blocks easier to find, and the 10 minute target is approached again. The reverse happens if hash rate rises. Live hash rate and difficulty are on the market context page. This page does not snapshot those figures, because they move continually.
Source: Bitcoin Core: src/kernel/chainparams.cpp: halving interval of 210,000 blocks, 10 minute block target, two week retarget, genesis block, Bitcoin Core: src/consensus/params.h: DifficultyAdjustmentInterval is nPowTargetTimespan divided by nPowTargetSpacing, Bitcoin developer documentation: Block chain guide: proof of work, difficulty every 2,016 blocks, block subsidy.
The security budget debate
Over the long term, as the subsidy shrinks, a larger share of miner revenue has to come from fees if total revenue is to stay meaningful in bitcoin terms. How large fee income will be in later eras, whether hash rate concentrates or disperses, and how that affects settlement security over decades, are open questions. They are not settled by any figure on this page. Companies cannot control them. A treasury policy should assume that network conditions can worsen as well as improve, and should not treat miner revenue as a company forecast. The same uncertainty is set out, without predictions, in Bitcoin's future: what companies should watch.
Source: Bitcoin developer documentation: Mining: proof of work, difficulty and the block reward, Bitcoin BIPs: BIP 42: A finite monetary supply for Bitcoin.
The four-year cycle idea
Some market commentary treats each halving as the clock for a repeating price pattern: that bitcoin has tended to rise in the year or two after previous halvings, and that the same shape can be expected again. That claim is about past prices, usually plotted from a very small number of events. This site does not repeat those price paths, does not give targets, and does not treat a halving as a reason to buy or sell.
The idea is contested for several independent reasons:
- A small sample. There have been four halvings. Four events are not a reliable basis for a repeating cycle, even if some past periods looked similar when drawn on a chart.
- Other drivers. Macro conditions, leverage and liquidations, and changes in who can hold bitcoin, all move prices. By the fourth halving on 20 April 2024, US spot bitcoin exchange-traded products had already been approved, on 10 January 2024. That is a different market backdrop from 2012, 2016 or 2020. Naming those facts is not a prediction of their effect.
- Each cut matters less in absolute terms. As set out above, 93.75% of the 21 million cap had already been issued by height 839,999. The next era issues at most 328,125 BTC, compared with 10,500,000 in the first era. A story that treats every halving as an equal supply shock does not match the schedule.
Source: SEC: Release No. 34-99306 (January 10, 2024): order approving the listing and trading of spot bitcoin exchange-traded products, mempool.space: Block 840,000, the fourth halving (20 April 2024), Bitcoin Core: src/validation.cpp: GetBlockSubsidy, 50 BTC halved every 210,000 blocks, Bitcoin Core: src/consensus/amount.h: COIN (100,000,000 satoshis) and MAX_MONEY (21 million BTC).
Past halvings are history. They record what the software did, and what the market around them happened to do, on those dates. They are not a template for the next one, and they are not a trading signal for a company treasury.
What it means for a company
For a company that already holds bitcoin, a halving changes nothing in the company's own wallets, books or tax by itself. Balances do not split or shrink. Keys, descriptors and backup plates are the same the day after the block as the day before. Nothing about a halving changes the site's custody guidance: companies should not rely on a single signature for company funds. See custody options.
Keep halving headlines out of treasury decisions. Purchase, cap and sale rules belong in the written policy, not in a reaction to coverage of the date:
- Size the holding from cash above a protected reserve, and from a cap the company can live with, as set out in the sizing guide.
- Write those rules down before they are tested, in the treasury policy.
- If the policy includes a rebalancing or sale trigger, follow that trigger, with the approvals and records in selling and rebalancing. Do not invent a new trigger because a halving is near.
A practical board habit is to put the estimated month on the board calendar as a reminder to re-read the policy, not as a prompt to act. When headlines spike, staff and directors may be asked what the company is doing. A short, pre-agreed line helps: the holding is unchanged, the policy is unchanged, and the company is not treating the date as a reason to buy or sell. The issuance chart on the supply curve page, the live countdown on market context and the calendar are enough context for that conversation.
Accounting and tax are where the UK and the US can differ, even though the protocol event is the same. Choose your country.
The short version: UK
- The halving does not move the company's coins and is not, by itself, a disposal for Corporation Tax.
- Tax usually looks at what happens when the company sells, swaps or spends bitcoin, not at a protocol date.
- Under FRS 102, many companies carry a holding at cost less impairment, so a later price move is not automatically booked as profit or loss. Revaluation is a separate, judgemental policy choice. FRS 105 allows historical cost only.
- A burst of headlines can still change the market price you see; that is not the same as a tax event, and it may not change the accounts either.
UK: accounts and tax
UK accounts depend on the framework the company uses. Under FRS 102, a holding is often treated as an intangible asset (or, in some cases, inventory) and may be carried at cost less accumulated amortisation and impairment. A rise in the market price is not recognised under the cost model until a disposal. Whether the revaluation model is available depends on whether fair value can be determined by reference to an active market, which is a judgement. FRS 105, for micro-entities, allows historical cost only. None of those measurement choices is triggered by a halving. See UK accounting under FRS 102 and FRS 105 and FRS 102.
Source: FRC: FRS 102: The Financial Reporting Standard applicable in the UK and Republic of Ireland, FRC: FRS 105: The Financial Reporting Standard applicable to the Micro-entities Regime, ICAEW: Accounting for cryptocurrencies under FRS 102 (helpsheet).
For tax, HMRC treats cryptoassets as a matter of the company's facts, and looks at disposals. The protocol reducing the subsidy paid to miners does not transfer the company's holding. If the company later sells or otherwise disposes of bitcoin, the usual Corporation Tax rules on that disposal apply, including pooling. See company bitcoin tax in the UK.
Source: HMRC: CRYPTO40100: Conversion to sterling and accountancy.
The short version: US
- The halving does not move the company's coins and is not, by itself, a taxable disposal.
- The IRS treats virtual currency as property. Tax usually looks at sales, exchanges and other dispositions.
- Under ASU 2023-08, in-scope crypto assets are measured at fair value, with changes going through net income, for fiscal years beginning after 15 December 2024.
- So a price move around a much-discussed date can show up in reported profit or loss for a US GAAP company even when no bitcoin was sold. That is an accounting effect, not a reason to trade.
US: accounts and tax
Under FASB ASU 2023-08, in-scope crypto assets are measured at fair value at each reporting date, and gains and losses from remeasurement go through net income (Subtopic 350-60). The standard is effective for fiscal years beginning after 15 December 2024, including interim periods. A later swing in the market price, including one that happens to sit near a halving, can therefore change reported earnings without any on-chain movement. That is why a board should already understand the accounting, from the US accounting guide, rather than discovering it from a headline.
Source: FASB: ASU 2023-08, Intangibles: Goodwill and Other, Crypto Assets (Subtopic 350-60).
For federal tax, Notice 2014-21 treats virtual currency as property. A taxable event generally needs a sale, exchange or other disposition. The subsidy changing for miners is not, by itself, such a disposition of a company's existing holding. See company bitcoin tax in the US.
Source: IRS: Notice 2014-21: virtual currency is treated as property for federal tax purposes, IRS: Digital assets.
Common questions
Does a halving change the bitcoin the company already holds?
No. Existing balances, keys and backups are unchanged. It is a change to how much new bitcoin miners receive for new blocks.
When is the next halving?
At block 1,050,000. The month is an estimate. This page and the calendar currently show around April 2028, based on the 10 minute target and the height checked on 10 November 2026, and they update from mempool.space when scripts can run. Treat the date as movable until the block is mined.
Should the company buy or sell because a halving is near?
This site makes no price predictions and does not recommend buying or selling around a halving. Follow the written policy, including its sizing and rebalancing rules. If those rules do not mention the halving, that is a reason not to improvise a new one.
Why do people talk about a four-year cycle?
Because the subsidy interval is about four years at the target block time, and because some commentators have drawn price patterns around the four halvings so far. A sample of four events, with other drivers in play and a shrinking absolute subsidy, is a weak basis for a company decision.
Does it change our tax bill or our accounts?
The event itself is not a disposal. In the UK, cost-model accounts often will not recognise a later price move until a sale. In the US, ASU 2023-08 can take fair value changes through net income at a reporting date. Ask your accountant how your framework applies. The protocol date does not, by itself, create a tax bill.
Will fees replace the subsidy?
That is an open question, not a forecast. Recent quiet windows have shown fees as a small share of miner revenue, but fee share varies with demand for block space. See the security budget section above and the future watch list.
Common mistakes
- Treating a halving date as fixed. It is an estimate until the block is mined.
- Changing allocation or sale rules because of halving headlines rather than the written policy.
- Treating four past halvings as a reliable four-year price cycle, or as a reason to buy before the next one.
- Confusing a cut in new issuance with a change to coins the company already holds.
- Taking a single week's fee share, or any miner-revenue figure, as a forecast of network security or of the company's own results.
- Forgetting that US fair-value accounting can show a profit or loss from a price move even when the company did not trade.
Read next
- The supply curve, issuance to 21 million, computed live.
- Market and network context, live height, subsidy and fees.
- Bitcoin calendar, the countdown and the dated halvings.
- Glossary: halving, the short definition.
- Treasury policy, write the rules down before they are tested.
- Sizing an allocation, cap the holding from cash above a reserve.
- Selling and rebalancing, triggers, approvals and records.
- Bitcoin's future: what to watch, including the long-term security budget question.
Sources
Primary sources only. Each link was checked on 10 November 2026. Rules change, so confirm the current version with your adviser.
- Bitcoin Coresrc/validation.cpp: GetBlockSubsidy, 50 BTC halved every 210,000 blocks
- Bitcoin Coresrc/kernel/chainparams.cpp: halving interval of 210,000 blocks, 10 minute block target, two week retarget, genesis block
- mempool.spaceBlock 0, the genesis block (3 January 2009)
- mempool.spaceBlock 210,000, the first halving (28 November 2012)
- mempool.spaceBlock 420,000, the second halving (9 July 2016)
- mempool.spaceBlock 630,000, the third halving (11 May 2020)
- mempool.spaceBlock 840,000, the fourth halving (20 April 2024)
- Bitcoin Coresrc/consensus/amount.h: COIN (100,000,000 satoshis) and MAX_MONEY (21 million BTC)
- Bitcoin BIPsBIP 42: A finite monetary supply for Bitcoin
- mempool.spaceChain tip height, 975,281 (checked 10 November 2026)
- Blockstream EsploraChain tip height, 975,281, agreeing with mempool.space (checked 10 November 2026)
- mempool.spaceREST API documentation: block height, hash rate, difficulty adjustment and fee estimates
- Bitcoin developer documentationMining: proof of work, difficulty and the block reward
- mempool.spaceMining reward stats for the 144 blocks ending at 975,281 (checked 10 November 2026)
- mempool.spaceMining reward stats for the 2,016 blocks ending at 975,281 (checked 10 November 2026)
- Bitcoin Coresrc/consensus/params.h: DifficultyAdjustmentInterval is nPowTargetTimespan divided by nPowTargetSpacing
- Bitcoin developer documentationBlock chain guide: proof of work, difficulty every 2,016 blocks, block subsidy
- SECRelease No. 34-99306 (January 10, 2024): order approving the listing and trading of spot bitcoin exchange-traded products
- FRCFRS 102: The Financial Reporting Standard applicable in the UK and Republic of Ireland
- FRCFRS 105: The Financial Reporting Standard applicable to the Micro-entities Regime
- ICAEWAccounting for cryptocurrencies under FRS 102 (helpsheet)
- HMRCCRYPTO40100: Conversion to sterling and accountancy
- FASBASU 2023-08, Intangibles: Goodwill and Other, Crypto Assets (Subtopic 350-60)
- IRSNotice 2014-21: virtual currency is treated as property for federal tax purposes
- IRSDigital assets
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