Key duplication means making a new key from the original, or from its code, that opens exactly the same lock. The same cuts are made on a key blank with the same profile.
We do not duplicate or copy keys. What we can tell you is how to keep track of how many keys to your door exist, which is what really matters for your security.
With a basic lock cylinder, anyone who has had your key for a while can get another one made without you knowing. With high security lock cylinders that have a protected key, new keys can only be ordered by showing the key security card, which you keep. If you have let the house or had building work done, think about how many people have had your keys.