Also known as 'standard broadband', an ADSL connection is delivered through copper telephone lines, with average download speeds of 8Mbps.
Although undoubtedly the slowest type of broadband on the market, speeds offered with ADSL are still sufficient for those with a low reliance on the internet.
It can also be accessed almost anywhere in the UK, making it popular in areas where superfast and full fibre broadband is unavailable.
ADSL key points
- ADSL stands for Asymmetric Digital Subscriber Line
- Unlike other types of broadband such as full fibre, ADSL is available in almost every area of the UK.
- It requires an active phone line to work.
- Although the most widely available type of connection, it is also the slowest, and therefore no longer recommended unless you have no alternative or only use the internet for low-bandwidth activities, such as online banking.
What is ADSL internet and how does it work?
An ADSL connection works by sending data and voice along a fixed single copper phone line (PSTN). The PSTN, short for Public Switched Telephone Network, is the same line you use when making an ordinary call from your home phone.
Because you will be using this same line to access both the internet and your landline, when ADSL is installed, a DSL (Digital Subscriber Line) - also known as a splitter - is used to separate the broadband and voice signals. A splitter is what allows you to be online and use your home phone at the same time.
ADSL has average download speeds of 8Mbps, but as this connection relies solely on copper wires, performance is dictated by how near or far your home is located from the nearest telephone exchange. The closer you live to the exchange, the better connection and stronger signal you'll have.
Conversely, if you live further from the exchange, or if the copper cables supplying your connection are frayed or degraded, your connection will likely be much slower.
The download and upload speeds you'll actually get will be confirmed by your chosen provider before installation.
What is the difference between ADSL and ADSL2+?
An upgrade to ADSL, ADSL2+ has improved range and can achieve download speeds of up to 24Mbps - three times faster than ADSL. But these higher download rates will only really be accessible if you live close to the telephone exchange (ideally within 5km).
However, with either ADSL and ADSL2+, the bandwidth is shared between a large number of users, meaning that the performance of the connection can be highly variable - especially if you live further out from the nearest telephone exchange or are accessing the internet during peak times (usually between 4 - 8pm).
Which providers offer ADSL broadband?
Most Internet Service Providers (ISPs) who use BT's Openreach network still offer ADSL broadband packages. However, with the PSTN switch-off planned soon (more on that below), some providers have stopped offering these types of broadband deals altogether.
Which broadband providers offer ADSL deals?
The majority of ADSL deals available will quote average download speeds of between 8 and 11Mbps and upload speeds of 1Mbps. Below is a list of providers who still offer these deals.
Offered through their 'Brilliant Broadband' package, NOW Broadband's ADSL deal has average download speeds of 11Mbps, and includes fee-free activation, as well as phone line rental.
Plusnet's ADSL deal has average speeds of 10Mbps and includes line rental as standard. Like most providers, Plusnet also includes a free wireless router, as well as fee-free activation for new customers.
The ADSL deal with TalkTalk has 11Mbps in average download speeds and is priced at £24.95 per month on an 18-month contract. Although a free router is included, setup costs of £9.95 will apply for new sign-ups.
What is the PSTN?
Standing for 'Public Switched Telephone Network', the PSTN has been in use since the 1800s. It uses copper telephone wires to provide homes and businesses across the UK with a reliable means of communication.
But the PSTN is now considered a 'legacy network' and is due to be switched off completely by BT Openreach in December 2025.
Is ADSL being phased out in the UK?
BT Openreach - who has the biggest broadband network in the UK - rents out its services that work on the PSTN (ADSL, superfast broadband) to ISPs through what is known as Wholesale Line Rental (WLR). ISPs who rent these services are known as 'Local Loop Unbundling' (LLU) providers.
Once the PSTN network is switched off, these LLU providers can still offer broadband deals, but only full fibre.
To meet the goal of switching off the PSTN, BT Openreach formally introduced its 'stop sell' on sales of new WLR services on the 5th of September 2023.
What is the 'Stop Sell'?
'Stop Sell' means that once more than 75% of an exchange area is able to access full-fibre, standard (ADSL) and superfast (FTTC) broadband will no longer be available to new and existing customers.
So, if you live in one of these exchange areas and are currently on an ADSL or fibre connection with an LLU provider, you don't need to switch to full fibre just yet. However, the next time you change your broadband deal, you will need to switch to full fibre.
If your existing broadband deal is due to expire after the are looking to upgrade your broadband service, use our postcode checker to see what deals are available in your area.
Only users of MPF-based services are currently exempt from the switch-off.
What is MPF?
The Metallic Path Facility (MPF) is when a provider takes over both the broadband and voice services on a copper phone line.
MPF is a legacy technology that lets providers deliver phone and broadband services over copper telephone cables. This includes ADSL, superfast (FTTC) broadband and home phone services. MPF is also referred to as a "fully unbundled loop" or "classic local loop unbundling".
Broadband providers who use this method of unbundling - such as Sky and TalkTalk - are currently unaffected by the PSTN switch-off and the Stop-Sell.
Why is the PSTN switch-off happening?
BT has stated that the PSTN network is not only old, but that its technology is failing to keep up with current demands for internet and communications services.
Switching to an entirely digital network will mean that households and businesses will receive overall faster and more reliable internet, as well as a clearer signal with phone services.
I want to keep my home phone after the PSTN switch-off. What can I do?
If you use your landline to make calls and don't want to lose this service, most broadband providers will continue to offer deals that include a home phone package using Voice over Internet Protocol (VoIP).
What is VoIP?
Voice over Internet Protocol (VoIP) - also known as Digital Voice or IP voice - is a digital voice service that allows you to make and receive voice calls using an internet connection instead of relying on copper telephone wires.
But it's not just landlines that will use VoIP. Right now, every time you use your laptop or smartphone to call someone via the internet, you are using VoIP. For example, when you make a call over apps like Skype, FaceTime or Whatsapp, you are using VoIP.
What are the benefits of moving to digital voice services?
Upgrading to digital voice services will mean being able to make and receive calls with little-to-no static or interference. You'll also have the ability to make multiple calls at once, as well as access your landline from locations other than home.
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