Yes, it is currently capped at 21m. But it is just a line of code. enter image description here Anybody can go and change it to whatever they want and what is needed then is to persuade the miners to accept it. Blockchain provides immutability of data already on the blockchain but nothing stops people from changing the code.

It's just that.

There is no need to persuade Bitcoin wallet users.

So why are we seeing a media message that there can only be 21m BTC in circulation where this is strictly speaking not true.

It could be more.

What we need is just an agreement of miners that they are happy. And given the hashrate it would take less than ten mining pools to get 50%+ hashrate. Not much.

Obviously mining pools would not make such a decision because it would hurt their interests and BTC main selling point is that there can be only 21m BTC in cicrulation but ... they could make such a decision at some point.

Please correct me if I am wrong.


  • Your assumptions are incorrect: it is network nodes that enforce the rules. If the miners attempt to change the rules (ie, hardfork to increase supply), the nodes will simply ignore those blocks as invalid.
    – chytrik
    Sep 18, 2021 at 22:29
  • See also: bitcoin.stackexchange.com/a/106830/63872
    – chytrik
    Sep 18, 2021 at 22:30

1 Answer 1


Like you've mentioned Bitcoin does not only works because of the software powering it. There is a also a general social contract or agreement around Bitcoin definition, which include the 21M limit.

For example, if another inflation bug would happen in the future, allowing an attacker to break this limit, I'm very confident the Bitcoin network would accept a hard fork in order to restore the 21M limit (I'm not talking about the disastrous short/medium term consequences around such bug though).

Yes, part of the network could decide to hard fork and increase the limit as well. This would require changing the Bitcoin emission rate at some point in the future. At this point if you run your own node, you will simply reject the blocks with a coinbase transaction adding too many Bitcoin on the network. A hard fork happen and people choose which rules they want to follow.

So, stating that there never be more than 21M Bitcoin is quite right, otherwise, it's not Bitcoin, just another fork.

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