Simplify Networks is a top managed services provider offering solutions Rack & Stack, Installation, IMAC, hosted phone systems, cloud solutions, SIP trunking, call center services, dedicated servers, and call recording.

Phone lines for the system you already have

If you run your own phone system, SIP trunking is simply how the calls get in and out of it. It replaces the old physical phone lines with a connection over your internet, which is cheaper to run and far easier to change when your business does.

There is now a deadline attached to this. Openreach is switching off the traditional ISDN and analogue phone network in January 2027, and as of early 2026 around half a million UK business lines still had not moved. If your phone system is still connected to ISDN lines, it will stop making and receiving calls when that happens. SIP trunking is what replaces them, and it is a straightforward change if it is done before the rush rather than during it.

We supply and support business SIP trunks for companies across the UK, and we look after the connection rather than leaving you to work out why a call failed.

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What this means in practice

You keep your existing phone numbers and your existing phone system. What changes is how the calls reach you, and what you pay for them. Adding or removing lines takes minutes rather than an engineer visit and a wait for the exchange, so you are not paying all year for capacity you only need in December.

It works with the systems businesses actually have. We connect SIP trunks to 3CX, FreePBX and Asterisk, and to Avaya, Mitel, Panasonic, NEC and Yealink systems that are still doing their job perfectly well. If your system is old enough that it only accepts traditional lines, we will say so and tell you what the options are, including a small gateway that lets it carry on.

Moving your numbers across is a standard porting process. We handle the paperwork with your current provider, it typically takes one to two weeks, and the number does not go dead in between. If your office moves, the numbers move with you. If the building loses internet, calls can be diverted to mobiles automatically rather than ringing out to nobody.

Because we are field engineers first, this is not a case of posting you a router and wishing you luck. Our own engineers across England, Scotland and Wales can be on site for the changeover, and if something needs a person in the building afterwards, one turns up.

Straightforward pricing

What it costs

Pricing is per channel, where a channel is one call happening at a time. A ten-person office usually needs three or four. Tell us roughly how many calls you handle at once and how many numbers you need, and we will give you a monthly figure on the first call rather than after a discovery process.

Common questions

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