Telephone Lines

T2K provides businesses with the full package, including telephone lines. We deal with any line changes needed from start to finish, taking any pressure and hassle off your shoulders. 

Having the right lines in place is crucial for all businesses, no matter what size. Having the wrong lines in place could have detrimental effects on a company such as: poor business continuity, no remote support, bad customer service and unnecessary fees.


Multiple Line Options

T2K provides customers with multiple line options, including PSTN, ISDN2, ISDN30 & SIP. We will advise you on your best options dependant on your requirements.


HD Call Quality

T2K offers SIP lines with offer HD voice call quality. This is essential for businesses across the country to thrive. Poor call quality can lead to misheard information and loss in sales.


Hassle Free

T2K undertakes all aspects of your lines. If you're confused about what lines you require, don't be. T2K will advise on the best lines suited for your business and undertake the installation.

Looking For Telecoms Specialists? Contact Us Today.

What Are Telephone Lines?

Telephone lines are the hidden infrastructure that connect homes and businesses across the UK with internet and telephone communications.


Without telephone lines, businesses across the UK would be without any sources of communications. In the UK there are different phone lines available, however by 2020, only SIP (VoIP) will be available for businesses. This is where calls are made through the internet.


Generally speaking, SIP allows for better call quality, along with lower costs. SIP allows businesses to access greater flexibility and further options within their telephone system to harness its full potential.

What Are My Options?

You have multiple options when it comes to choosing the lines for your telephone system, however some are better than others for different businesses. 


Firstly, you should know that T2K recommends the best suitable lines for your business, so if you're confused about telephone lines and what's best for you, don't be!


The main lines are ISDN2, ISDN30 and SIP. However, BT have announced that ISDN lines will become phased out by 2020 in favour of SIP.


T2K would recommend preparing ahead of the move. If you have a Mitel system, we would recommend moving to SIP. For smaller businesses it may be beneficial to opt for a pay-as-you-grow hosted telephone system.



What Lines Do I Need?

Firstly, you should know that T2K recommends the best suitable lines for your business, so if you're confused about telephone lines and what's best for you, don't be!

The main lines are ISDN2, ISDN30 and SIP. However, BT have announced that ISDN lines will become phased out by 2020 in favour of SIP.

T2K would recommend preparing ahead of the move. If you have a Mitel system, we would recommend moving to SIP. For smaller businesses it may be beneficial to opt for a pay-as-you-grow hosted telephone system.

I Think I'm Paying Too Much For My Lines, Can You Help?

If you think you're currently paying too much for your telephone lines by your current supplier, T2K offers a bill analysis service, absolutely free of charge. We would recommend that you view the cheaper lines & calls page here.

Why Is Everyone Moving To SIP?

You may find that many people are making the transition over to SIP now to avoid the mad rush of the 2020 ISDN termination. 

SIP allows you to achieve higher quality calls - generally at a lower call cost.

Many businesses find that SIP allows them to access a wider range of features within their business telephone system.

Learn More About Moving Over To SIP Here

I'm Looking For A New Supplier For My Telephone Lines, Can You Help?

Yes, T2K can definitely help! If you're looking for a new supplier for your lines, we would recommend that you contact us through the form on our contact us page or call our head office directly on 0808 202 3200.

Additional Phone Line Information

If you're still not 100% au fait with telephone lines and which solution your business may require, don't worry.


We recommend that you contact our head office directly to receive knowledgeable information about telephone lines on 0808 202 3200.


Understanding The Lines

PSTN Lines (Analogue)

PSTN stands for Public Switched Telephone Network, and is a traditional land line. This is the same sort of line you might have at home as well as in your office. It can provide basic features such as Caller ID and Call Diversion but is limited to a single telephone number no matter how many lines you actually have. Each line is provided on a separate pair of copper cables form the local BT exchange and the telephone number on the line is tied to that BT exchange.


Analogue lines, made from copper, are primarily used for voice traffic, franking machines as well as fax and PDQ machines. A PSTN line can also be connected to a modem for a dial up internet connection, although, this technology is becoming obsolete.


Unlike ISDN, phone numbers are not tethered to a set location, giving SIP trunking the benefit of portability.


Businesses can automatically divert calls to a separate office location if all the lines at one office location are occupied (even if your offices are located in separate countries), and should your business choose to relocate, your current numbers move with you.


Having too many or too few channels is a familiar problem for most businesses with ISDN. With no limitations on DDI ranges and as many as 2,000 channels on a single connection, SIP eliminates this issue by enabling businesses to instantly scale, up or down, on a per channel basis to reflect their fluctuating needs.


ISDN2 stands for Integrated Services Digital Network and is also known as Basic Rate Interface, or BRI for short and these are Digital Lines. As suggested in the name, an ISDN2 solution allows the user to make two calls at once.


ISDN2 is the equivalent of two digital telephone lines, otherwise known as channels. Two channels can work independently allowing you to make a call, use the internet or receive a fax at the same time.


As the connection is digital, there is the added benefit of increased clarity for voice calls at 64 KB per second in comparison to 56 KB with traditional analogue lines. As a result, larger data files and emails can be sent and received more quickly and securely.


If your business requires further connections further down the line you can add further ISDN2 circuits to the existing setup in pairs.


ISDN30 is also known as the Primary Rate Interface, or PRI for short. While having the same features as ISDN2 the difference is the number of channels involved. ISDN30 has a minimum of 8 channels to be installed and can be increased 1 channel at a time up to 30 channels on a single connection but multiple connections can be added to give 60, 90 or even 120 channels. It is a perfect solution to a large business with multiple line requirements.


ISDN30 is a high-performance voice and data service for modern businesses. Their digital technology gives higher line quality; which allow for:

  • Rapid connection
  • Clear voice communications with other ISDN users
  • Ideal for networks linking two or more offices
  • Provides staff with individual DDI numbers


With an ISDN30 System you can have an unlimited number of DDI numbers (Direct Dial), allowing your customers and business contacts to dial directly through to staff members, without passing through a switchboard.

Our Core Values

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    Your Business Makes Our Business

    We're passionate about what we do, and your business is our priority - without it we don't have one. That's why we only fit the most up-to-date equipment at the best price possible for you. All of this, paired with the best support we can provide. You could consider us geeks when it comes to telecoms systems.

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    Only The Most Qualified For The Task

    All of our engineers have the correct Mitel and Gamma Horizon accreditations to install and support your system. You should be safe in the knowledge that any support you receive will be the best at all times.

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    Two Ears, One Mouth

    We operate with the philosophy; two ears one mouth. Listening to your needs and requests first, then advising from our experience and expertise, taking into consideration your budget and requirements to provide you with the perfect telephone system for your business. 

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    The Full Package In One Place

    We take care of it all from start to finish, no matter what telephone system you require. We supply, Install and maintain all of our systems. Giving you that priceless peace of mind that there won't be too many cooks involved into the mix. 

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    A Genuine Value-For-Money Service

    Quality is key to a long lasting telephone system. Regular maintenance and well-sourced, up to date products, are at the forefront of our business. With that in mind, you can be rest assured that your spend becomes an investment into a properly working, long lasting system that will serve you for years to come.

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    We're Not Satisfied Until You Are

    We take pride in our work, carrying out installs as if they were our own property. If you’re not satisfied with any aspect of the work carried out, we're not either. We try, where possible, to make the system as unobtrusive to your office decor as possible; concealing cabling, holes or system components along the way.

UK Wide Installation, Repairs & Maintenance - Contact Us Today

Contact Us

Here at T2K, we believe that there is no question too big or too small. Whatever your enquiry may be, from pre-sales, support and costs of products, we can help you every step of the way.


Please use our contact form to contact us. We aim to get back to you within 24h, although this will probably be quicker.


If you're a little bit form-shy, give us a call. Our friendly and helpful engineers or pre-sales team will do everything they can to make sure you get the help and support you need with every phone call you give us.


Call now on 0808 202 3200.