Three locks on three different keys — rekey them all, or replace one?

Question

Three locks on one house, photos attached: two nightlatches on one style of key and an older knobset on its own, so three keys on the ring. Not urgent — they wanted the three locks rekeyed and asked what it would cost.

Accepted Answer

For this we would normally replace the knobset and rekey the other two locks to the new knobset, so all three work on the same new key. It works out about the same money as three straight rekeys, but you end up with one key for the lot instead of three. And next time the keys need changing it is one lock to rekey, not three. The rule of thumb: when one lock is the odd one out, replace it to match the others rather than rekeying it into the set. Two locks on the same keyway can be keyed alike. A third on a different keyway can't — it stays on its own key no matter how many times you rekey it. Real quote, September 2026: $396 inc GST.

Three locks on three different keys — rekey them all, or replace one?

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