Definition
Address reuse means accepting multiple payments to — or spending and then reusing — the same Bitcoin address. Although it feels convenient, it quietly dismantles the pseudonymity that Bitcoin's address model is meant to provide. Every transaction touching that address is permanently and publicly linked, and the address's full balance and spending history become readable by anyone who has ever interacted with it.
The Privacy Cost
When one address appears across many transactions, every counterparty — an employer paying a salary, a merchant, a friend — can watch how much you hold, when you move it, and where it goes next. Combined with the common-input-ownership heuristic, a single reused address can drag an entire cluster of otherwise-separate addresses into one identity. If just one of those addresses is ever tied to your real name through a KYC purchase or a shipping address, the whole cluster can be deanonymized.
The Security Cost
There is a technical dimension too. Spending from an address reveals its public key on-chain. With a properly implemented wallet this is safe today, but it removes a layer of defense — and in a hypothetical future where signature schemes are broken (for example by sufficiently powerful quantum computers), reused addresses with exposed public keys would be the first at risk.
The Fix
Use a fresh address for every receipt. Modern hierarchical-deterministic (HD) wallets generate a new address automatically from a single seed, so avoiding reuse costs you nothing in backup complexity.
To go further, see our notes on the Change Output and the Common-Input-Ownership Heuristic.
In Simple Terms
Address reuse means accepting multiple payments to — or spending and then reusing — the same Bitcoin address. Although it feels convenient, it quietly dismantles…