Strict circular economy within the Bitcoin network

Dear list,

This BIP proposes a consensus rule update to implement a strict circular economy within the Bitcoin network, keeping the 21 million maximum supply limit permanently intact.

An expiration limit is introduced for Unspent Transaction Outputs (UTXOs). UTXOs that exceed a maximum age threshold of `MAX_UTXO_AGE` (e.g., 1,048,576 blocks) will be deemed invalid for spending and pruned from the nodes' active Chainstate database. The nominal value of these expired satoshis will not be injected into immediate block rewards. Instead, they will be reintroduced into the pending emission reserve, dynamically extending the duration of halving epochs to guarantee a perpetual block subsidy without adding inflation.

https://github.com/bip-proposer/bitcoin-infinity/blob/main/infinity.md

I appreciate discussion on this proposal.

Best, Ricard.

Expiring UTXOs might be a step too far, especially when other projects considered state rent, where you pay more fees when you try to spend an old UTXO. Of course some UTXOs may never be spent, but that only means they are effectively out of circulation, giving more value to the mining rewards, whether these rewards are subsidy or fees. So miners win whether these old UTXOs move or don't, and if they move, miners eventually get rewarded for the marginal cost of storing these UTXOs for so long.

On Sunday, 28 June 2026 at 16:54:25 UTC+3 Ricard wrote:

> Dear list,
>
> This BIP proposes a consensus rule update to implement a strict circular
> economy within the Bitcoin network, keeping the 21 million maximum supply
> limit permanently intact.
>
> An expiration limit is introduced for Unspent Transaction Outputs (UTXOs).
> UTXOs that exceed a maximum age threshold of `MAX_UTXO_AGE` (e.g.,
> 1,048,576 blocks) will be deemed invalid for spending and pruned from the
> nodes' active Chainstate database. The nominal value of these expired
> satoshis will not be injected into immediate block rewards. Instead, they
> will be reintroduced into the pending emission reserve, dynamically
> extending the duration of halving epochs to guarantee a perpetual block
> subsidy without adding inflation.
>
> https://github.com/bip-proposer/bitcoin-infinity/blob/main/infinity.md
>
> I appreciate discussion on this proposal.
>
> Best,
> Ricard.
>