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PSTN and ISDN 2025 Switch OFF

In December 2025, the UK Public Switched Telephone Network (PSTN) will be switched off. It supports a range of telephone and broadband products, including basic telephone lines, multi-lines, ISDN2, ISDN30, ADSL broadband and Fibre to the Cabinet (FttC) broadband.

The Big Switch Off and Your Business

The switch off will likely affect alarm line companies, payment terminals, traffic light systems, payphone lines, emergency pendants, dialysis machines, telemetry devices and any other special service.

There is a 5-year plan to transition from PSTN based products to a new range of products. The replacement products include Fibre to the Premise (FttP), Single Order Generic Ethernet Access (SOGEA) and Cloud Telephony.

While 2025 seems like a long way away your business and your existing services may be affected earlier. It’s crucial to have a plan in place especially if you have multiple locations or are greatly reliant on your phone or broadband lines. 

Video Explainer

2025 Switch Off - Your Migration Plan

Oliver Lofthouse, Sales Director at Chess, summarises what the impact of the 2025 Switch Off is on your business and how to remove the stress from your migration plan and what you need to consider.

2025 Switch off Solutions

Connect your people

While 2025 seems like a long way away your business and your existing services may be affected earlier. It’s crucial to have a plan in place especially if you have multiple locations or are greatly reliant on your phone or broadband lines. 

There are two timelines to consider:

National PSTN Closure

• Impacts every exchange in UK

• Stop Sell of PSTN based products in September 2023

• PSTN based products need to be migrated to alternative products by December 2025

FTTP Priority Exchange Rollout

• Impacts individual exchanges

• 12 months’ notice of copper-based product stop sell when 75% FTTP availability

• Impacts businesses from June 2021

PSTN 2025 FAQs

What is the PSTN and ISDN Switch Off?

The Public Switch Telephone Network (PSTN) will reach its end of life in December 2025. The PSTN supports a number of Openreach products which Communication Providers (CPs) purchase at regulated pricing and often sell to businesses and consumers, wrapped up in their own line rental, broadband and call package deal.

These include Wholesale Line Rental (WLR), Shared Metallic Path Facility (SMPF) Broadband and Integrated Services Digital Network (ISDN). At the end of December 2025 traditional telephony, including fixed lines and services in the Public Switch Telephone Network (PSTN) will be switched off and withdrawn from service.

Openreach are adamant the December 2025 deadline is set in stone. PSTN Lines that have not migrated to alterative services in April 2025 will be deemed as Orphaned Assets and Openreach intend to work with CPs to identify and migrate customers to alternative products by the December 2025 deadline.

The Public Switch Telephone Network currently supports WLR, ISDN2 and ISDN30, Local Loop Unbundling Shared Metallic Path Facilities (LLUSMPF), Narrowband Line Share and Classic Products. This will in addition affect products such as Asymmetrical Digital Subscriber Lines (ADSL) Broadband and Fibre to the Cabinet (FTTC) Broadband. This is because the underlying line product is being withdrawn, therefore there is no underlying WLR telephone service to support the broadband.

When FTTP gets to 75% availability within a certain area, Openreach can designate that exchange as a Priority Exchange. At that point, a 12-month notice is given to stop the sale of copper-based products at premises where FTTP is available. If you want a new service or you want to switch suppliers, you will only be able to buy FTTP irrespective of whether you would prefer another service. 

Openreach has been rolling out the FTTP Priority Exchange program in tranches, with a new tranche being announced every three months. Currently, there are seven tranches, totalling 552 exchanges, which have been designated Priority. The first stop sell of copper-based products happened for 13 Priority exchanges in June 2021, with further stop sells completed over the year. The stop sells are set to continue throughout 2022, with tranches three to six taking place throughout the year, with tranche seven scheduled for the start of 2023.

In summary, there are two timelines to consider:

National PSTN Closure

Impacts every exchange in UK

Stop Sell of PSTN based products in September 2023

PSTN based products need to be migrated to alternative products by December 2025

FTTP Priority Exchange Rollout

Impacts individual exchanges

12 months’ notice of copper-based product stop sell when 75% FTTP availability

Impacts customers from June 2021

This is an ideal opportunity to get ahead of the curve, as many people will only focus on the future 2023 Stop Sell date, while missing on the opportunities that are available today.

The term stop sell is used by Openreach to signify stopping the sale of certain Openreach products. This is different from product withdrawal, as under stop sell, any end customer who already has the product, will be able to continue using it (until it is withdrawn).

If a product is impacted by stop sell, this won’t just mean no new supply, but also, you won't be able to do working line takeovers, start of stopped lines, migrations, CP transfers, addition of broadband to copper voice lines, bandwidth modify, or addition of lines and channels to existing installations.

Currently there are two programmes for which stop sell applies:

  1. FTTP Priority Exchange - If FTTP Priority Exchange stop sell applies in an exchange where you’re trying to put an order through, then as long as FTTP is available at that premises, it’ll be the only product you can buy, and other products (WLR3 Analogue, ISDN2, ISDN30, SMPF, MPF, FTTC, Narrowband Line Share, Classic, Gfast, SOGfast, SOGEA and SOTAP) will no longer be available to order.
  2. National WLR Withdrawal (September 2023) - If WLR Withdrawal stop sell applies in an exchange where you’re trying to put an order through, then certain products will be allowed/restricted as follows:

    Allowed Products – FTTP, SOGfast, SOGEA, MPF FTTC, MPF and SOTAP (in locations where FTTP, SOGFast or SOGEA not available)

    No longer available - WLR3 Analogue, ISDN2, ISDN30, SMPF, FTTC, Narrowband Line Share and Classic

The term End-of-Life or Withdrawal is used by Openreach to signify turning off certain Openreach Products. If a product is impacted by an End-of-Life or Withdrawal, this means that as of the End-of-Life/Withdrawal date the product will cease to function.

Currently there are three End-of-Life (Withdrawal) dates published:

  1. FTTP Priority Exchange Trial Site (Salisbury) - End of Life issued as 19th April 2023 (End of Life will not apply in premises where FTTP is not available or for certain exemptions/exclusions e.g. Special Service Devices, non-standard lines)

  2. National WLR Withdrawal Trial Site (Mildenhall) – End of Life issued as 19th April 2023 (End of Life will not apply in premises where FTTP or SOGEA are not available or for certain exemptions/exclusions e.g. Special Service Devices, non-standard lines)

  3. National WLR Withdrawal – End of Life date planned as December 2025

From September 2023 Openreach will issue a full “Stop Sell” of new supply WLR. When we refer to new WLR there is further clarification needed on what would be considered as a new supply. For example, does this include a transfer to another CP? 

As part of the nationwide PSTN, WLR and ISDN Withdrawal, from the end of September 2023 there will be no new line installations for both WLR and ISDN, including conversions of the WLR Line to an ISDN Line, increase of ISDN channels, change of address, start of a stopped line or working line take over. 

Get in touch with our expert team for a free consultation and find the best solution for your organisation. 

During the Public Switch Telephone Network closure, all these services need to be tested with new IP technology and the SO products. This means alarm line companies, payment terminals, traffic light systems, payphone lines, emergency pendants, dialysis machines, telemetry devices and any other special service must be tested by the equipment manufacturers. Openreach can provide line test facilities for testing equipment against their individual line configurations. 

We strongly suggest that you should engage with your special service supplier at the earliest opportunity to start the conversation about how you protect yourself moving forward. Get in touch with our expert team for a free consultation and find the best solution for your organisation.

Moving forward, Openreach products will be a Single Order (SO) variant of ADSL or Fibre broadband services. 

These products will become known as; Fibre To The Premises (FTTP) and Single Order Generic Ethernet Access (SOGEA) which is Openreach’s Broadband only FTTC replacement. 

When these Single Order (SO) broadband products are provided there will be no voice on the telephone line and no dial tone, this means the CP will need to provide some form of VOIP service like a Hosted PBX License or Session Initiation Protocol (SIP Trunking) service to provide the voice telephony element which would replace the traditional WLR or ISDN telephone line. 

These alternative products fall into two categories All-Internet Protocol (All-IP) & Metallic Path Facility (MPF) 

All-IP 

All-IP are a range of new products which are designed to deliver data only services, meaning they do not have a native ability to pass voice calls. 

There is a range of All-IP products either currently available or in development including FTTP, SOGEA, SOGFAST and SOTAP. These are effectively data only versions of GFAST, FTTC and ADSL (their old-world counterparts). More details on these products can be found here.  

All-IP products are a data-only service, and if you want to make calls, you will need to purchase an over-the-top Voice over IP product (VoIP). If you wish to retain your telephone number, you will need to port it to the VoIP supplier. 

If you use your current PSTN based service to make calls and want to continue to do so following migration to an All-IP product, then you will need to purchase an over-the-top VoIP service. 

If you have an existing phone system you want to retain, SIP would be ideal for you. *Link to SIP 

If you have simple voice requirements, then there are single voice line options designed to replace the old school analogue line. 

If you are a larger business, a feature-rich cloud voice system would be preferable. *Link to cloud voice 

MPF

MPF is a legacy technology, which came out of the deregulation or Local Loop Unbundling (LLU) of UK Telecommunications. LLU allows multiple telecommunications operators to use connections from the same local exchange. 

The switch-off of the PSTN does not impact MPF services. 

MPF services include Analogue Lines, ADSL and FTTC and have a native voice service included, so work with existing analogue handsets/wiring. 

MPF removes a requirement to purchase an over-the-top VoIP product. 

MPF is an alternative to SOGEA/SOTAP, in locations where FTTP is not available. 

Whether you need a phone line in addition to your broadband depends on what products are available at your premises. If you are not yet in a full fibre area, such as an area where your fibre is delivered from a fibre cabinet, it is only possible to supply this over a phone line. There could also be compatibility issues with 3rd party products, so speak to a Chess expert for specific advice.

Get in touch with our expert team for a free consultation and find the best solution for your business.

A digital phone line is simply a 'line' to make and receive calls like you’ve always done. A digital line is different because instead of using a traditional line, the technology uses your broadband/fibre connection.

Benefits of a Digital Line

  • Keep your existing number, even if you move premises. Your digital line number will be internet based which means you can take your number wherever you go.
  • Easy to use with simple installation
  • Making and receiving of calls is the same, but you have the additional portals and apps available to you. 

There are a range of services that work with digital lines and some cases where there isn't compatibility. We've outlined the most common services used alongside traditional lines and their compatibility with digital lines. If there is something not covered below, please get in touch to speak to one of our experts.

EPOS System

You can only currently use a system that runs over the internet and is not dependent on a phone number. Currently, a digital will not be compatible with restaurant and takeaway systems used to remember customers details or previous orders on the back of a telephone or online order.

Alarms

Alarm companies are now selling systems that do not rely on a traditional phone line. Instead, these systems can run off an internet connection. Alternatively, many suppliers can offer a system that runs over the mobile network. You’d need to ensure that any alarm you currently have or intend to purchase is the newer technology and is not dependent on a traditional analogue phone line.

Personal care systems or pendants

Personal care systems and pendants that do not rely on a phone line are suitable for use on a digital line. Please note, if your current or intended care alarm requires the use of a phone line then a digital line is currently not compatible with these products.

Lifts

A digital line is not suitable for a lift service. Please contact your lift company for further advice on alternative solutions.

Card Machine (PDQ)

Payment systems are increasingly modernising. so it's likely that a digital line will not prevent you from taking payments. You will need to ensure your terminal runs over the internet or mobile network and is not reliant on a traditional phone line.

London Oyster Card Machine

Unfortunately, the London Oyster Card Machine is not currently compatible with a digital line and instead relies on a traditional phone line.

Don't worry, features such as 1471, 141 and 1571 are still available on your new phone line. You just need to set them up again. You can read how to do this in our user guide on MPF Telephony features.