The main way to determine when a given bass or cello was built is its serial number. Derived from over 25 years of research, the Registry serial-number list is the standard reference for dating Kay instruments. You can view the list here.

Your instrument may not have an apparent serial number, or you may be considering purchase of an instrument and have no access to the number. Details of construction and finish can help determine a more approximate production date. Contact the Registry with any available details for an age estimate.

Register your instrument for a complete confirmation of the instrument’s age, authenticity and details of its place in the production history