Whether you're online every day, or just browse the web occasionally, you can select the right amount of data to suit you.

Don't forget, its not just surfing the internet that uses data - apps, music streaming, watching video clips and playing games all use data as well.

If your phone is compatible, all our data Bolt Ons will let you tether. We won't charge you anything extra, but we'll take any data you use out of your data allowance. And don't worry. You'll be able to change your data Bolt On each month if you decide later on that you need a different amount of data.

If you decide not to choose data with your tariff, you can still browse the internet on your mobile. You can use up to 50MB a day without ever being charged more than £1 a day. We don't recommend this option if you use a Smartphone, iPhone or BlackBerry.

If the data allowance you've selected comes with unlimited public Wi-Fi (through BT Openzone), this gives you access to Wi-Fi hotspots so you can use these rather than using your data allowance.