Abstract: A toll restrictor for use in determining whether attempts to complete a trunk call are unrestricted is responsive to at least a first successively dialed three digit code of the call from the trunk to provide a control signal in response to this code being a restricted code to prevent the completion of the call having this code. The restrictor includes a registration portion which comprises relay means responsive to the dialed digits for initially registering the first two successively dialed digits of the code as a first tens digit group and the last successively dialed digit of the code as a second ones digit group. The first tens digit group enables the provision of a family of ten three digit codes having a common first two dialed digits. The registration portion also comprises second relay means responsive to at least the first tens digit group for providing the control signal when at least the tens digit group indicates a restricted three digit code.