What speed can I get?
When you sign up with us, move home/office, or change your package, we'll give you an estimate of the speed you should be getting. For example, we might say you could get '16 to 18Mbps'. This is an estimate of your 'line speed' or 'sync speed' and the actual speed you get should fall somewhere within this range. It's what your broadband and router is capable of if everything's working at its best.
Line speed can change over time and you may find that it can change each time you re-boot your router. The distance from your home to the exchange or cabinet will affect it, and temporary factors like severe weather can degrade the quality of the line.
Your line speed will always be higher than your actual ('throughput') broadband speed, because it's far less liable to signal interference than the wireless connection within your home. This is why if you run a speed test over Wi-Fi you'll find that the speed test results will always be less than your line speed.
You can find out exactly what your line speed is by logging into your router and looking for your 'sync rate'. How you do this will vary, depending on your router. Our help pages show you how to log into your router and check your connection status and sync rate.
You can't improve your speeds if they are within your estimates.
What is line speed and throughput speed?
Line speed
Your line speed, also known as your sync speed, is the maximum speed at which your router can connect to the Internet. You can check your line speed by logging into your router and looking for your 'sync rate'. How to do this will vary depending on your router. Our help pages show you how to log into your router and check your connection status and sync rate.
Line speed can change over time and you may find that it can change each time you reboot your router. The distance from your home to the exchange or cabinet will affect it, and temporary factors like severe weather can degrade the quality of the line.
Your line speed will always be higher than your actual (throughput) broadband speed, because it's far less liable to signal interference than the wireless connection within your home.
Throughput speed
Whereas your line speed is a measure of how well your line can carry data to your router, the actual speed you see when you're online depends on many other factors. Most speed checkers will show the speed at which data is downloaded to your PC, laptop, tablet or phone – this is known as your throughput speed.
Throughput speed will always be slower than your line speed. It can be affected by different things, like the website you're on, your Wi-Fi connection, if you're online at a busy time, how many people are sharing your connection, and the quality of your telephone line.
A quick and easy way to check your throughput speed is to go to mybroadbandspeed.co.uk and follow the steps to run a few tests. If the results are slower than the estimate we gave you when you first signed up, have a look at our problem-solving tips.
You can also run a more detailed speed test at BT Wholesale.
What’s the difference between standard and fibre broadband speeds?
Standard broadband speed
You can get up to 17Mbps, but the actual speed you'll get is affected by:
how far you are from the telephone exchange - the further away you are, the slower it'll be
the quality of your phone line - if it's in poor condition, it won't be as fast
the type of broadband available where you live - in some places, BT's lines don't support speeds of up to 17Mbps, so you might only be able to get speeds of up to 7.5Mbps.
Fibre broadband speed
- You can get up to 76Mb, but the actual speed you'll get is affected by:
- how far you are from the green cabinet - the further away you are, the slower it'll be
- the quality of your phone line - if it's in poor condition, it won't be as fast
- the package you chose - Up to 38Mbps packages are available and, depending on your line speed estimate, you might be able to upgrade to Unlimited Fibre Extra which provides speeds of up to 76Mbps.
How fast will my broadband be when I first get it?
When we first set up your broadband, we won't know exactly how fast it'll be. It'll take a little while to get to a more settled speed. Here's what you can expect.
The first ten days
To find out your eventual speed, we'll run some tests from your telephone exchange. Because of that, the speed will go up and down and you might get disconnected a few times. But don't worry, that doesn't mean there's a problem; it just means we're trying to find the best balance between speed and reliability for you.
After ten days
Your broadband will settle into a speed close to the estimate we gave when you signed up. Small changes are normal and nothing to worry about. If there's a problem affecting your connection, the speed will slow down for a while to give you the most reliable service possible.
What sort of things can slow down my broadband?
Broadband faults
Any fault will slow down your broadband, especially if it keeps disconnecting because of it. When that happens, it can take up to three days before it goes back to normal while we test and adjust your connection to find the best, most reliable speed.
Faults on the line
If there's a fault on the phone line, you may have trouble connecting to the Internet. Usually, when the phone line is fixed, your connection will go back to normal. But because that's happened, the speed will drop for the next few days while we sort out your connection again.
Using Wi-Fi
If you're online using Wi-Fi, several things can slow down your connection. These include things like how far away you are from your router, whether you have thick brick walls, or any interference from household appliances. If that's the case, try our tips for getting a better Wi-Fi signal.
Household appliances
Household appliances like cordless phones, baby monitors and microwaves can cause interference, especially to Wi-Fi, and slow your speed down.
Not using microfilters
A micro-filter is a device that has a plug and two sockets. If you don't have two sockets on your master socket you'll need a filter on every phone socket that you're using in your home. You plug it into your phone socket in the wall and then plug your broadband and phone cables into it. It stops the two signals interfering with each other.
Note: If you do have a modern 2-socket faceplate with a socket marked ‘Broadband’ or ‘ADSL’ you mustn’t use a separate microfilter – just plug your router directly into that already-filtered socket.
Bad weather
Heavy rain and thunderstorms can play havoc with your broadband. They can even damage your equipment permanently. If there's a really bad storm, it's a good idea to unplug your broadband router until it's over.
Your computer
If you've got an old computer (more than three years old), it might be slower because it's having trouble running the latest software and programs; so when you go online, it seems as if it's your broadband that's slow. Older laptops may also have slower Wi-Fi because of the network cards in them.
Viruses also slow everything down, so make sure your computers are protected against them.
Busy times
Even though our network won't slow down noticeably at peak times, some specific websites or downloads might.
How can I make sure I’m getting the fastest speed possible?
There are some things you can do to help it be as fast as possible.
Leave your router switched on
It's best to leave it on, even at night. When you switch it off and on a lot, it makes it look like your line's unstable. When that happens, your telephone exchange will temporarily make your speed lower because it thinks your line can't cope with anything higher.
Check your Wi-Fi signal
Using Wi-Fi? If you've got a lot of devices connected at the same time, it'll slow down your connection. If you're using a desktop or laptop, try connecting it to your router with an Ethernet cable.
Use microfilters
A microfilter is a device with two sockets that you plug into your phone socket in the wall. It'll stop your broadband and phone line from interfering with each other. If you don't use one, your broadband could be slower, not work at all, or you might hear a high-pitched noise when you make phone calls.
You need a filter on every phone socket that you're using in your home (unless your master socket has two sockets with one dedicated to broadband already). So, as well as the phone socket you use for your broadband, make sure you use a microfilter in any other phone sockets that are used for:
- phones
- set-top boxes
- burglar alarms
- fax machines
- Try not to use phone extension cables
- Extension cables can cause interference on the line, which slows down your broadband. It's better to use Wi-Fi if your router and computer are too far away from each other to connect with a cable. If you do need to use a phone extension cable, make sure it's new, high-quality and as short as possible.
Use the master socket
This is the best place to plug in your router. You'll usually find it where your phone line comes into your home.
Some homes don't have master sockets. In that case, use the one closest to where your phone line comes into your home. Have a look at our video if you'd like to find out more.
What if I am unhappy with the speed you are providing?
If we cannot provide a speed equal to or better than the Minimum Guaranteed Access Line Speed we promised you, you should contact our support team and we'll work with you to try and get the matter resolved. You can see Ofcom's speed code of practice for more information on what this means.
Should our faults team confirm there is nothing that can be done to resolve your fault, you have the right to leave without paying any Early Termination or Cease Fee charges. If you want to do this, you should speak to our Customer Services Team.
We may provide offers but these do not impact your right to leave your contract with us if your line rate remains less than your Minimum Guaranteed Access Line Speed.