Why some keys copy cleanly and others do not
A clean original key usually copies better than a worn one. If the key is bent, cracked, badly rounded, or only works when wiggled, copying it may copy the problem too. In that case, the lock or code may need to be checked.
Home, business, and vehicle key differences
House keys, mailbox keys, padlock keys, commercial keys, chip keys, and remote keys are not the same job. Some keys need a specific blank, some need authorization, and vehicle keys may need programming in addition to cutting.