What is data?

Whenever your device connects to the internet and you’re not using wifi, you’ll be using mobile data. Just like making calls and sending texts, you’ll be able to use mobile data wherever you receive signal – this could be 5G, 4G or 3G. Almost all tariffs come with a data allowance, typically in GBs (gigabytes) or with unlimited data.

How to track your data usage

Make sure you’ve registered for My O2. One of the many things you can do through My O2 is see how much of your monthly data you’ve used – and what you have left. You can download the My O2 app or log in to My O2 online.

We’ll also text you when you’ve used 80% of your data allowance, and then again if you reach 100%.

What to do if you run out

If you use up your monthly data allowance, here are some options to stay connected to the internet:

  • Add a data Bolt On in My O2.
  • Change your tariff through My O2. If you’re often running low, moving to a tariff with a higher data allowance could be the answer.
  • Use wifi – you can stick to using wifi until your allowance is refreshed.

Want more from your data?

How your data gets used

Streaming films, tv shows, videos and music, as well as sending emails with large attachments, eats lots of data. Here are some examples to help you understand how much data you’ll use:


Without attachments, the average email uses between 10 and 30KB of data. With attachments, it can be anything from 500KB for one photo, to several MB for large documents.

Social media

Sites such as Facebook, Twitter and Instagram can quickly burn through your data. Tweeting a message uses about 500KB, but if you're uploading lots of photos, it'll eat up more.

Apps and games

Downloading a game uses around 30MB. Playing games online may drain your data quickly. It could be anything up to 60MB an hour, or more.


Downloading one song uses around 3 to 10MB.

Video clips, TV shows and films

In HD, an average video clip uses 3MB. 95MB for a TV show and 570MB for a film.

You can also use your phone as a personal hotspot. That means when you connect another device to your phone’s mobile data. But keep in mind hotspotting can eat up a lot of data, so try to avoid doing that too often and keep a closer eye on your usage.

Wondering how much data you need?

1GB a month is roughly enough to:

  • browse for 11 hours
  • send 16,000 emails without attachments or 300 with attachments
  • download 17 songs
  • watch 40 minutes of TV.

3GB a month is roughly enough to:

  • browse for 33 hours
  • send 50,000 emails without attachments or 1000 with attachments
  • download 50 songs
  • watch 120 minutes of TV.

30GB a month is roughly enough to:

  • browse for 330 hours
  • send 500,000 emails without attachments or 10,000 with attachments
  • download 500 songs watch 1200 minutes of TV.

Keeping up to date with your data usage

You can download the My O2 app. Sign in, go to My Allowances and choose Data. You'll see a breakdown of all the data you've used and what's left. Alternatively, sign in to My O2 online.

To help you stay on top of your data usage, we'll text you when you've reached 80% of your allowance and again when you've reached 100%. Once you’ve used up your monthly allowance, you’ll need to buy more to get back online.

You could buy a one off Bolt On through My O2 to keep you going until your next bill date. Or increase your monthly data package so you don’t have to worry about running out of data again.

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