VoIP Savings Calculator UK 2026

Switching from traditional landlines to VoIP typically saves UK businesses 30% to 50% on their monthly phone bills, with cloud-hosted VoIP plans starting from £8 per user per month compared to £15 to £25 per channel for legacy ISDN connections plus separate call charges. For a 20-person office spending £800 per month on traditional phone services, moving to a mid-range VoIP solution at £20 per user per month would reduce the monthly bill to £400 — an annual saving of £4,800. The transition is no longer optional for many businesses: BT is switching off the Public Switched Telephone Network and all ISDN services by January 2027, meaning every UK business still using traditional phone lines must migrate to a VoIP-based system. One-off migration costs include IP handsets at £50 to £200 each and number porting fees of £5 to £15 per number. This calculator compares your current phone system costs against VoIP alternatives to show your potential annual saving.

How to Use This Calculator

Enter the number of phone lines or users in your business.

Input your current monthly phone bill — include line rental, call charges, and any maintenance contracts.

Select a VoIP plan level to compare: basic, professional, or enterprise.

Review your annual saving including year 1 costs (handsets and setup) and ongoing savings from year 2.