Necessary Party

Also referred to as an indispensible party or compulsory or compelled party, a necessary party is one who as a matter of procedural law must be a party to a lawsuit, thus for example in US law the patent owner as well as an exclusive licensee must typically be a party to a claim of infringement of the patent. Failure to include a necessary party can and will usually result in a motion to dismiss for failure to join a necessary/indispensible party.