A key system patent protects you from unauthorized key manufacturing, distribution, and duplication. However, patents do expire. What happens when the patent expires? Just because the patent expires it does not mean that your cylinders are going to stop working, or fall off the door. Operationally the cylinders and keys are fine. What patent expiration does mean though is that the original manufacturer can no longer legally control the manufacturing and distribution of after-market key blanks that match your keyway. After-marketing key blanks are “open to the public” and are no longer restricted. Knowing how the manufacturer handles keyways after the patent expires is extremely important. You will want to ensure that even though the patent expires, the manufacturer still honors the original Key Control Agreements that were signed when the system was first purchased. This means that the manufacturer will still limit orders for cylinders, cut keys, and key blanks for your system to only authorized individuals at your facility. The manufacturer should also agree that your custom coined keys and key blanks will continue to NOT be sold to anyone except the original facility, and only with proper authorized signors. The alternative to this of course, is that the patent expires and the manufacturer opens up purchasing of your keyway and key blanks to anyone with an account. Language to use in key system specification:The manufacturer shall continue to enforce its key control policies and ordering authorization/verification for cylinders, cores, cut keys, and key blanks for the life of the key system, even after patent expiration.