SIP & VoIP
Modern alternatives to traditional telephone lines.
Traditional analogue and ISDN lines are being retired. SIP and VoIP deliver your calls over your internet connection instead — usually at lower cost and with far more flexibility.
What this means for your business
VoIP simply means your calls travel over a data connection rather than an old copper phone line. In practice, the phone still rings and customers notice nothing except better call quality.
SIP trunks suit businesses that want to keep an existing on-site phone system for now. Hosted VoIP replaces it entirely. We'll explain which route fits your current setup and timescales.
Why businesses move
- Lower line rental and call costs
- Keep existing business numbers
- Add or remove channels quickly
- Calls continue if a site is unavailable
- Works with remote teams
- Readiness for the analogue switch-off
SIP trunks
Connect your existing phone system to modern lines without replacing hardware yet.
Hosted VoIP
A full cloud phone system with no on-site equipment to maintain.
Number porting
Bring your existing numbers with you, subject to provider and number eligibility.
Call quality
We check your broadband is suitable before recommending voice over it.
Pricing guidance
SIP trunk typical monthly ranges.
Priced per channel, plus your numbers and call bundle.
| Option | Typical range | Basis |
|---|---|---|
| SIP channel | £4–£8 | per channel / month |
| Number rental | £0.50–£2 | per number / month |
| UK call bundle | £3–£8 | per channel / month |
| Porting existing numbers | £0–£25 | per number |
Is this right for you?
- Rule of thumb: about one channel per three to four users.
- Keeping a working on-site PBX? SIP is the cheapest modernisation step.
- PBX end-of-life? Compare against a cloud phone system before renewing.
Indicative UK market ranges to help you budget — not a quote. Your actual price depends on user numbers, site count, contract length and what's already installed. We confirm every price in writing before anything is ordered.
Get started
Explore VoIP for your business
Tell us what you have today and we'll set out the practical options.
Related services
Ready to simplify your business telecoms?
Whether you're reviewing your broadband, replacing an old phone system, renewing mobile contracts or simply want to understand whether you're getting good value, Ademco can help.