Bitcoin's total supply is capped at 21 million coins. Once all are mined, no new bitcoins will enter circulation. This fixed supply makes Bitcoin inherently deflationary, unlike fiat currencies that central banks can print indefinitely. With a diminishing issuance rate each year, scarcity increases, which historically has driven value appreciation due to supply-demand dynamics. Deflation is a core feature of Bitcoin’s value proposition.
Although the Bitcoin network will continue operating similarly after all coins are mined, miners will face significant changes. Miners currently validate transactions and secure the network by solving complex cryptographic puzzles. For each block added to the blockchain approximately every ten minutes, miners receive a fixed Bitcoin reward—known as the block reward.
Initially set at 50 BTC per block, this reward halves every 210,000 blocks (roughly every four years) in an event called the halving. Over time, rewards have decreased to 25 BTC, 12.5 BTC, and now 6.25 BTC after the third halving in May 2020. The next halving is anticipated in 2024. Until the final Bitcoin is mined, miners will continue earning block rewards, but once the supply is exhausted, this revenue stream will cease.
Over 18.69 million BTC (89% of the total supply) have been mined in just over a decade. Interestingly, estimates suggest the last Bitcoin won’t be mined for another 120 years due to increasing computational difficulty.
What Will Miners Do After the Last Bitcoin is Mined?
Once all 21 million bitcoins are mined, miners will still participate in block discovery but will no longer receive block rewards. However, they will retain another source of income: transaction fees.
Currently, transaction fees constitute a minor portion of miner revenue. For example, daily block rewards are approximately 900 BTC, while fees range from 60 to 100 BTC—making up at most 11% of total earnings. By 2140, when block rewards vanish, fees will account for 100% of miner income.
Transaction Fees Are Already Significant
In December 2017, when Bitcoin’s price was around $14,000, daily transaction fees peaked at 1,495 BTC. Miners earned $21 million in fees that day—about half their block reward earnings. Since then, users have paid over $500 million in fees due to network upgrades and transaction batching.
During periods of high network activity, fees spike dramatically. In May 2021, average fees surged past $59, a 300% increase from earlier that month. As Bitcoin adoption grows, competition for block space will intensify, driving fee revenue higher. Coupled with potential price appreciation and lower energy costs, mining could remain profitable long-term.
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What If Miners Go on Strike?
If miners reject the fee-based model and cease operations, how would the network respond? A reduction in mining participation would lower the total computational power (hash rate). Bitcoin’s protocol automatically adjusts puzzle difficulty to maintain a 10-minute block time. Fewer miners mean less competition, potentially increasing rewards for those who remain—assuming Bitcoin retains value.
If all miners stopped, the network would halt. New transactions would go unconfirmed, though the historical ledger remains publicly visible. Without new blocks, Bitcoin would become functionally useless. Yet, miners are unlikely to abandon revenue entirely; they could simply switch to other cryptocurrencies. Rational actors rarely leave money on the table.
Could Miners Turn Malicious?
Bitcoin occasionally experiences temporary forks when two blocks are mined simultaneously. The shorter chain is discarded, invalidating its transactions. A 51% attack occurs when a malicious miner controls most of the network’s hash rate, allowing them to reverse transactions by creating a longer alternative chain.
In a reward-free future, miners might exploit fee mechanisms. For instance, a miner could withhold a block and convince others to extend it with reduced fees. If this chain surpasses the honest chain, the attackers could rewrite transaction history—e.g., reversing a payment to effectively double-spend coins. Such behavior could become more common if fees alone inadequately incentivize honesty.
However, executing a 51% attack requires overwhelming computational resources. As long as Bitcoin’s network remains robust and decentralized, the cost of attacking it would likely exceed potential gains. Only a catastrophic drop in participation would make this feasible.
Frequently Asked Questions
What happens when all Bitcoins are mined?
The network will continue operating, but miners will rely solely on transaction fees instead of block rewards. Transactions will still be verified, and the blockchain will remain immutable.
Will transaction fees be high enough to sustain miners?
If adoption increases, fees could rise due to block space competition. Historical data shows fees can already generate substantial revenue during peak usage.
Can the Bitcoin protocol change to continue rewarding miners?
While technically possible, altering Bitcoin’s fixed supply would require consensus and undermine its core value proposition. Such a change is highly unlikely.
What prevents miners from attacking the network?
The immense cost of acquiring 51% of the network’s hash rate acts as a deterrent. Additionally, attacking a valuable asset would degrade its worth, harming the attacker.
How long until the last Bitcoin is mined?
Based on current halving schedules, the final Bitcoin will be mined around the year 2140.
Could miners switch to other cryptocurrencies?
Yes. Miners often shift resources to more profitable coins. Bitcoin’s longevity depends on its ability to remain economically viable for stakeholders.