I cant split cash, but i can split bitcoins?

sep 2025

Bitcoin does not store balances. It only tracks unspent transaction outputs, called UTXOs.

A UTXO is a chunk of bitcoin created by a past transaction that has not been spent yet. Your balance is just the sum of the UTXOs you control.

You cannot partially spend a UTXO. You must spend it fully and receive change as a new UTXO.

Correlate this with the case of currency. A 10 dollar bill cant be split into 2 five dollars directly. Instead, a 10 dollars is paid, and the return is provided as different bills

The same is the case with bitcoin.

If someone wants to spend 0.3 BTC but only has a 1BTC UTXO, they spend that UTXO completely. The transaction creates one output of 0.3BTC for the receipient and another UTXO of 0.7 BTC back to the sender as change.

Each UTXO can be spent only once. This single rule prevents double spending.