Systems and methods for duplicating keys are disclosed. A key duplication system receives a key blank into a key receiving module. The key receiving module includes opposable jaws that assist with alignment of the key blank within the module. The key receiving module also includes an end stop that engages the tip of the received key blank and is linearly displaced as the key blank is further inserted. The linear displacement of the end stop is compared to a known value corresponding to a length of the shank of the key blank, and if the displacement does not match the known value, the user is instructed to re-orient the key blank.