Business telephone systems are often broadly classified into key telephone systems and private branch exchanges, but many combinations (hybrid telephone systems) exist.

A key phone system, or key system for short, is the oldest and simplest multiline business phone system among the three types. It is landline-based, which means it transmits signals converted from audio …

Nov 24, 2025 · Key systems are characterized by having buttons on each phone corresponding to specific lines (outside lines or extensions), allowing users to directly select a line for outgoing calls or …

Aug 7, 2024 · In this post, we’ll review three different types of business phone systems: key phone systems, private branch exchanges, and Voice over Internet Protocol. We’ll explain what they are, …

Jun 11, 2025 · A Key Telephone System is a type of telephone system designed for businesses, allowing multiple lines to be managed from a single device. The term "key" refers to the buttons or …

Feb 26, 2025 · A Key System Unit (KSU) is a business phone system designed for small to medium-sized enterprises (SMEs). It acts as a central switchboard that helps manage multiple phone lines …

A Key Telephone System (KTS) is the traditional phone system having phones with multiple keys/buttons and lights that indicate which line (s) are in use at any given time and typically have one …

Sep 7, 2023 · A Key Telephone System (KTS) is a communication system predominantly used in businesses, which allows multiple telephones to share a certain number of outside lines for making …

Aug 6, 2025 · This guide breaks down the types of business telephone systems, who they're best suited for, and what to avoid — especially for small and mid-sized businesses.

Feb 5, 2021 · We’re here to clear things up. We’ll explain what a key system is, what a PBX system is, and how the two compare―both historically and modernly. (And we’ll point you toward an alternative …