Check for a manufactures stamp on the lock face plate.
How to identify manufacture of your door lock.
Cheap low quality and mass produced locks often do not come with key codes.
Knockoffs are blank faced like this one.
Morticed or on sits on the outside rim what locking mechanisms are on the lock.
Genuine kwikset deadbolts have the name kwikset embossed in bolt s face plate on the edge of the door older ones say kwikset right on the faceplate of the lock.
Is the lock on the chiselled into the door.
These can be rekeyed using kwikset keys and factory tumblers as key cylinder dimensions are usually identical.
They are generally accepted as being more secure than the standard spring lock because they cannot be opened unless a key is used to rotate the lock cylinder to the open position.
From the different types of locks deadbolts are the ones most commonly used for front doors.