Calls, Lines & Voice

We offer a range of services, carriers and technologies when it comes to calls, lines and voice services. We specialise in 10 users and above but can help small businesses too.

With BT / Openreach having advised that the ISDN and PSTN networks will be shut down from 2025, now is the ideal time to look at replacing the old technology with something that us future proofed.

Take a look at below to see how we can help, whether you need a temporary telephone number on a building site, or a company wide telephony system for hundreds of people..

VOIP / SIP / Future Voice

We work with a number of major hosted voice platforms which run voice traffic over the internet or private circuit connections.

Voice Over IP and Session Initiated Protocol are phrases you may hear when people refer to these types of service.

Whether you run over the public internet, or over private networks allowing Class Of Service, we can provide a range of versatile “Future Voice” services from a range of carriers. Ideal for businesses who want to add lines to suit seasonal change in business, if growing rapidly, landline numbers to mobile, to provide out of area numbering (any dial code to any location) or people who need a temporary line for a project perhaps.

Phone Systems

Is your existing system getting a little tired? Do you want to bring your business into the 21t Century with a system that can link to your CRM and business systems? We can evaluate your needs, run a system audit if required and advise the best way to go moving forward. With new and pre loved systems available please ask a specialist how we can assist.


Traditional copper telephone lines are often referred to as PSTN. These can be used to make voice and fax calls on with a single number. PSTN lines are also needed to deliver ADSL and FTTC broadband services.


ISDN stands for Integrated Services Digital Network and comes in 2 flavours. Copper ISDN2e lines are used for voice and data communications and start from 2 channels (lines) per ISDN pair. You can add further connections (in pairs) up to 8 channels which increases the number of simultaneous connections and or available bandwidth. Call quality with an ISDN2 line will nearly always be clearer and sharper than a standard phone line too.


ISDN connections are in effect, digital exchange lines. They allow the digital transmission of voice and data over ordinary copper telephone wires, bringing better voice quality and quicker data transfer speeds.

Often used by SME or large business customers, ISDN30e allows you to create and launch your own-branded digital telephone services. It provides access and support calls, including calls over the networks of other communications providers. ISDN30e can provide up to 30 x 64k channels. Normally delivered over an E1 fibre connection but copper available also.

Note: ISDN & PSTN Switch Off

BT have announced that it will be switching off the ISDN network for data and voice calls, starting with a cease in supply after 2020, before full migration taking place at some point in 2025.  Right now 2025 may seem quite a way off, but the supplying of new ISDN will stop from 2020 and may well push businesses to migrate away from ISDN sooner rather than later. 

What does this mean to you as an ISDN user?

Despite an exact date in 2025 not yet having been confirmed, organisations still using ISDN will need to make plans to migrate away from ISDN by 2025. Businesses may well find they will start to struggle to purchase new or replacement hardware and could find that repairing any faulty ISDN based equipment may not be cost effective.  

What are the benefits of changing now?

Moving from ISDN to Cloud Voice before the cut off date is possible and you may find it beneficial for the reasons below.

1- Flexibility

Cloud Voice has the capability to support both single and multi-site customers including mobile and home workers.

2 – Work from anywhere

The easy to use mobile and desktop apps mean you can make and receive calls even when away from the office. Plus, the online portal and apps can be accessed from anywhere to manage any changes.

3 – Work more efficiently

Utilise tools such as conferencing, instant messenger,  desk sharing and presence.

4 – Control costs and make savings

Maintenance included, free calls between internal users and unlimited UK calls options are available

5 – Customised features

So you only pay for what each user needs with the ability to add features as you need them. 

6 – Support when it is needed

Get an initial familiarisation handover call, PLUS a variety of expert support options to help you get the most from your telephony solution including: online training modules,  training “passports” and also on site training packages through our service team.

I still have quite some time left on my ISDN contract

We might be able to help you migrate, even if you are still in contract on your ISDN.

Why use HM Network for your Hosted Voice?

As a BT Authorised Partner, HM Network can offer the same products plus more than the likes of BT Local Business. 

HM Network will take away your ISDN switchover headaches by providing you with a single, straightforward point of contact. You don’t have to worry about remembering who your account manager at BT was, if they are still there from when you signed your contract. We do all the necessary communication with BT for you.

Please call 0333 344 4190 or email and our specialists will be only too happy to help.


  • Future Voice

  • Geo / Non Geo Numbers

  • Out of area numbers

  • PSTN

  • ISDN2e

  • ISDN30e

  • VoIP

  • SIP Trunks