A punch block[1]​ (in English punch block) is a type of electrical connection used in telephony. It is so named because solid copper wires are connected to short slots with a sound similar to the onomatopoeic "punch." These slots are known as "insulation displacement connectors" and are generally placed across the width of a plastic insulating bar. They contain a pair of metal blades that cut the insulation from the wire as it is inserted into the slot. These blades also hold the wire in position and make electrical contact with it.

A punching tool is used to insert the wire firmly and properly into the slot. Some tools will cut excess wire.

Punching blocks are very quick and easy for connecting wires, as there is no insulation removed from the wires manually and there are no screws to loosen or tighten. These blocks are frequently used as patch panels or patch boxes for PBXs or other switched telephone systems with 21-pin RJ-21 connectors. They are occasionally used in other audio playback applications, such as in reconfigurable switch panels.