Relay UK (text relay service)

What's Relay UK?

If you have trouble hearing or speaking on the phone, you can use the Relay UK text relay service to help you. When you make a phone call with your smartphone, tablet or computer using this service, a Relay Assistant will act as a go-between for your conversation.

You just type what you want to say and the Relay Assistant will relay your words to the person you need to speak to. The Relay Assistant can also type the words the other person says to you, so that you can read it.

You need to download the Relay UK app onto your computer, iPhone, iPad or Android phone or tablet. Just search for ‘Relay UK’ in your app store. Then you can use the Relay UK app with a phone call to make your text calls. Find out more about Relay UK.

Once you’re set up and ready to make calls, these are the prefixes you need:

To make emergency calls: 18000

If you have trouble hearing/speaking: 18001

To call someone who has trouble hearing/speaking: 18002

The person you’re calling doesn’t need the Relay UK app to receive a call from you using text relay. However, if you need to call someone else who also has trouble speaking or hearing, then they can get the app as well and you can make a call where a Relay Assistant will type for both of you (text-to-text).

By using the Relay UK app you can communicate using text direct with other people if they have the app or a textphone. If they don't, a Relay Assistant will be automatically connected to relay your call.

  • 18000 – free
  • 18001 – calling standard UK landlines and mobiles - free
  • 18001 - calling non-standard numbers, for example non geographical or premium rate numbers - you get 60% off the cost of the call
  • 18002 – uses up any monthly minutes you've got, or if you don't have any, you'll pay standard rates


If you’re a pay as you go customer, you might need to top-up before you make a call. There are lots of different ways you can do this. If it’s your first time topping-up then you can do this online or by using a digital voucher.

If you’re a pay monthly customer, calls to non-standard numbers will come out of your safety buffer. You can increase your safety buffer, or make a payment on your account by calling 4488 from your Tesco Mobile phone.

All text relay calls use up a small amount of data from your allowance or bundle if you have one, otherwise it’s standard rates. The only prefix that also uses up minutes is 18002.

You can also set up a dedicated mobile number that uses text relay for all your incoming calls. People who call you will pay their standard rates for calls they make to you, and you’ll use up data and/or minutes, as we’ve described above.