With regards to VoIP (Voice over Internet Protocol) phone system, the terms "seat," "extension," and "line" have specific meanings:

• Seat:
• In a VoIP phone system, a "seat" typically refers to a user or an individual user license. Each seat represents a connection or authorization for one person to use the VoIP phone system. It includes the necessary features and functionalities for that user, such as voicemail, call forwarding, and other telephony services.
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• Extension:
• An "extension" in a VoIP phone system is a specific number assigned to a user or a device within the system. It is a unique identifier that allows calls to be routed to the correct destination. Extensions are often used for internal calls within the organization. For example, if a company has extensions ranging from 100 to 199, each employee might have a unique extension within that range.
• Line:
• A "line" in a VoIP system typically refers to a communication path or channel that enables a call. In traditional telephony, a line was often associated with a physical telephone line. In VoIP, it represents a virtual connection that allows voice communication. The term "line" can be used interchangeably with "channel" or "call path" in the context of VoIP.

As a rule of thumb, if your business employs 12 staff, you may size your VoIP system as follows.

• No of Seats/license – 12 (equal to the number of staff)
• No of extensions – 12 to 20. 1 for every staff, additional extensions will be used for your departments.
• No of lines – 6 (concurrent call capacity). I am using a 2:1 ratio between seats to lines. This assumes that all your staff will not be using the phones at the same time.

The above calculation is provided for a base line analysis, and it can vary from business to business.

In summary, a "seat" is the overall user license, an "extension" is the specific number assigned to a user or device or a department, and a "line" is the communication path that facilitates voice calls within the VoIP system. These terms help manage and organize the use of the VoIP phone system in a business or organizational setting.

It's recommended to consult with a telecommunications specialist or one of our business consultants to assess your specific needs and to determine the most cost-effective solution for your business.