Cloud PBX is a service that provides the functions of a traditional office-installed PBX (Private Branch Exchange) in the cloud. Since it operates via the internet, extension calls and external calls can be made from any location - office, home, or on the go. Adoption has surged, driven by the spread of remote work following the COVID-19 pandemic.
The biggest difference from on-premises PBX is the hardware ownership model. On-premises requires purchasing and installing dedicated equipment with initial investments of hundreds of thousands to millions of yen, plus self-managed maintenance and upgrades. Cloud PBX uses a monthly subscription model (approximately 1,000-3,000 yen per user per month) with no equipment purchase or maintenance required. Adding or changing locations can be done instantly from a browser-based management console, with flexible scaling for employee count changes.
Cloud PBX's weakness is its dependence on internet connectivity. If a line outage or ISP failure occurs, all calls go down. With on-premises, calls can still work over phone lines even if the internet is down. To compensate, redundancy measures such as using mobile lines as backup or contracting with multiple ISPs are recommended. Call quality is also affected by bandwidth and latency, making QoS configuration to prioritize voice packets essential.
Feature-wise, built on VoIP technology, advanced functions like IVR (interactive voice response), CTI (computer telephony integration), call recording, and call analytics are often included as standard - features that would require additional investment with on-premises systems. Installing a dedicated app on smartphones turns personal mobile phones into company extensions, also reducing the cost of issuing company phones. Combined with virtual phone numbers for business, even more flexible phone environments can be built.