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Internet data allowances - how much is enough?

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Mobile data usage: the basics

Data allowance can feel like a minefield to most consumers. While the cost of data continues to drop, the growth in apps and services that utilise ever more data means that it’s harder than ever to work out just how much you need.

And that’s before you’ve analysed which networks have the best deals when it comes to using data–hungry tools like Netflix, Spotify and Facebook.

Whether you’re looking to curb how much data you use or are keen for a package that will allow you unfettered access to the fastest data networks, our guide has got you covered. Read on and we’ll explain everything, from how data is measured to how you can avoid paying over the odds.

Want to know how much data you need? Check out our data calculator tool

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Mobile data usage: The basics

When you're downloading a movie or streaming a playlist over 3G, 4G, or even 5G, you’re using up precious data. But consumers remain unclear as to how much data they’re actually using each time they open an email, use FaceTime or scroll through Twitter. And that means millions are paying for data they don’t need, just to be on the safe side.

Research released by Citizens Advice in January 2019 found that a massive 71% of people on SIM-only deals were overpaying for data they did not use. It said that on average, consumers were not using 2GB of their data allowance each month, totalling £800 million a year. What’s more, it reckons consumers could save £63 per a year by switching contracts.

Worryingly, it also discovered that those who took out contracts with networks in–store were left with 4.2GB of unused data each month, with those who did so online winding up with 2.6GB of wasted data.

“Mobile companies should be doing more to help their customers save on data they don’t use, especially when it’s clear people are consistently underusing their allowance,” said Gillian Guy, CEO of Citizens Advice.

How is data measured? What do MB and GB stand for?

In store

Before we get into working out how much data you need, we should probably get you up to speed with the terminology for measuring units of data, which in turn is used by networks to tell you how much data you get with a contract.


This stands for megabyte and is made up of approximately 1000 kilobytes.


This stands for a Gigabyte. About 1000 megabytes makes up one GB.

The amount of data you get with your contract differs hugely. Some offer as little as 500MB (0.5GB) per month and start from under £10 per month.

At the other end of the scale, there are costlier data plans that offer comparatively vast allowances of 30GB or even unlimited data.

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How can I check how much data I'm using right now?

Checking stuff(

Checking exactly how much data you're getting through is easy. All you need to do is log in to your account on your computer by visiting your network's website.

Or if you're with one of the larger networks, you can log in to your network's customer account app on your phone.

Once you're logged in, you'll be able to see how much data you've used so far this month, as well as in previous months.

If you're often left with lots of unused data, you’re probably paying for a data allowance that's too generous for your needs.

Accessing your account on your computer is just a case of visiting your network's website and logging in. Then simply navigate to the section of the app that covers your data allowance.

However, using an app to check your data usage isn't quite so simple. That's because networks don't usually pre-install their customer account apps on phones at the point of purchase, so you may need to download the app first.

Handily, here are links from major network where you can get their customer-account apps:

What constitutes a heavy data user? Or a light one?

Heavy data users

A less precise but quicker way to get an idea of what sort of data allowance you need is to check which of these user profiles you match.

Low data user - 'I'll use it every so often, to keep up with friends and interesting news'

You like to look at web pages, or check your email.

You check your Facebook or Twitter online reasonably often.

You don't play a lot of games on your phone or download music directly on the phone.

You may occasionally use your mobile for chatting online or watch the odd video clip.

You're unlikely to use your internet for more than an hour a day.

Sound like you? If so, you're low data user and you’ll find that a low data allowance of 2-5GB will cover you.

Medium data user- 'I need it for my email, social media and for entertainment’

You download email daily to your phone, via an on-board or downloadable email client such as Gmail.

You spend quite a bit of time browsing the internet, and download a few games or applications a month.

You like to watch video on online streaming sites such as YouTube every so often and perhaps download a few songs now and then too.

Sound familiar? That means you're classified as a medium data user. You'll require a data allowance of 10GB per month at least.

Heavy data user -'I rely on my phone for both entertainment and work'

You send and receive quite a few emails daily, often with attachments.

You watch videos online several times a week and are likely to download a lot of applications and games as well as music for your phone.

You also make extensive use of streaming services, such as Netflix and Spotify.

You rely on your mobile internet for work as well as communication with friends and family and need to use your phone for internet access several hours daily.

Does that match your usage habits? Yes? That means you're classified as a heavy user. To ensure you never run out of data, you’ll probably need a monthly data allowance of around 20GB.

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How much data do I need?

using smartphone

With more and more apps requiring access to data services, it can be hard to work out what apps use how much data.

You can check exact usage on your phone. If you have an iPhone, fire up Settings, tap Mobile Data and scroll down to see which apps are using the most data. The one that’s eating up the most will appear at the top of the list.

Android users simply need to tap into the Data Usage menu in Settings to see a detailed graph of how their data usage has changed over the previous months, as well as a list of apps that are hoovering up the most data.

While these tools are great for giving you an overall picture of how much data you’re using, it’s good to know how specific services and usage breaks down too. The following is a good guide:

  • Streaming one hour of video on Netflix, iPlayer or Amazon Prime – 644MB
  • Streaming a two-hour movie in high definition – 4.2GB
  • Gaming online for an hour – 43MB
  • Streaming an hour of music via Spotify or Apple Music – 80MB
  • Browsing through 60 web pages – 140MB
  • Download one song – 4–8MB
  • Download a film trailer – 60–100MB
  • One hour of driving while using Google Maps – 5MB

With this information and an honest assessment of how you use your phone (for instance, how often do you stream music?), you should be able to make a pretty good guess at how much data you'll get through.

So, if you love watching movies via Netflix over 4G, you’re going to need bigger data allowance. If you only access the web or open email on your phone, then a smaller allowance should suit your needs.

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How can I save data?

Running low on data is a familiar problem for many of us. And when the alternative is forking out for a costly add-on on top of your monthly phone bill, lots of users opt to struggle by with the allowance they’ve got rather than buy more.

But it doesn’t have to be that way. Below we’ve compiled a list of tips to help you get more out of your monthly data allowance without costing you more money.

Download services over Wi-Fi so you can use apps offline

Wi–Fi is your friend when it comes to saving data. Regular home broadband or public Wi–Fi hotspots mean you can download whatever you need before you head out and shift to 3G or 4G networks.

Netflix, Amazon Prime and BBC iPlayer all allow you to download programmes over Wi–Fi, meaning that as long as you have enough storage space on your smartphone, you can stash whatever shows you want to watch without having to use data. This is particularly handy for train journeys, where 4G network access can patchy.

Likewise, Spotify and Apple Music allow you to download offline music, so you can listen to playlists, albums and podcasts without having to stream them. This will save data and also keep your battery kicking for longer, as it doesn’t have to work as hard by pulling information across the network.

Remember, too, that Google Maps allows you to download entire towns, cities and regions, meaning you can use your phone in Airplane mode and still get from A to B. This is particularly handy when travelling abroad and you’re concerned about using data.

Find out how to use Google Maps offline.

What are data–free services? And how do networks’ offers vary?

The growth of data rollover has come at the same time as more networks offering data–free services. This means that users can access certain services without them eating into their data allowance, meaning they can either cut back on their package or use it for other services.

Three’s Go Binge lets you stream Netflix, TVPlayer, SoundCloud and Deezer without eating into your monthly data allowance. So you can watch your favourite shows and listen to music without using any data or having to download anything.

Virgin Media customers on select plans can use WhatsApp, Facebook Messenger and Twitter without eating into their monthly data allowance.

Voxi lets you use social media sites like Facebook, Facebook Messenger, Instagram, WhatsApp, Pinterest, Snapchat, Twitter and Viber without eating into your data allowance.

Data rollover plans

Data rollover hero image people using phones

Networks are increasingly wising up to users having data left at the end of their monthly billing cycle and allowing them to roll it over into the following four-week period.

Sky Mobile is the best example of this, as it allows you to rollover any unused data at the end of each month and store it in an online ‘piggybank’. That data will be there whenever you want to use it for up to three years at no extra cost.

iD Mobile lets you roll on one month’s worth of unused data, which stops you building up a huge trove of unused data. But because any rolled over data from the previous month is used first, any data that’s left at the end of month can then be rolled over again.

Virgin Media also lets customers rollover one month’s worth of data at a time. But, just like iD Mobile, you use any rolled over data before your regular monthly allowance.

Vodafone customers on a pay as you go Big Value plan can rollover any unused data at the end of the month. But you can only rollover one month’s leftovers at a time, so you can’t stockpile endless data.

O2 customers can rollover any unused data to use the following month. But this only applies to additional data purchased on one of O2’s bolt-ons.

For more information, take a look at our guide to data rollover.

Flexible contracts

If your data usage varies a lot month to month, a flexible contract might be the perfect solution. Rather than tying yourself into a set monthly allowance for the next two years, you can now choose a tariff that lets you change it up every month.

So if you know you’re going to be using your phone a lot over the next month, you can choose to up your data allowance. Or if you’re paying for more data than you’re using, you can downgrade your monthly contract to a cheaper one with a smaller allowance.

O2, for example, offers a range of flexible contracts to help you manage your monthly allowances.

Sky Mobile also lets you increase or decrease your data allowance whenever you want, so you’ll always have the amount that suits your needs.

For more data-saving tips, check out our guide on how to limit your data usage.

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I’m going abroad for a few weeks. How can I use my phone while I’m away without running up a huge bill?


With horror stories of holiday-makers receiving huge bills for using their phones abroad, it’s easy to see why people are wary of switching on their devices when they’re out of the country.

But there are lots of ways you can use your mobile wherever you are in the world without it costing you a fortune.

Thanks to EU legislation passed in June 2016, you can now use your mobile phone data anywhere in the European Union without it costing you any extra.

And if you’re going outside the EU, there are lots of networks that give you the option to use your phone without it costing you a fortune.

Three lets you use your monthly allowance for no extra cost in 71 locations worldwide, including USA, Australia and New Zealand.

EE customers on a 4GEE Max plan get inclusive roaming in 52 locations worldwide. These include EU countries as well as the USA, Canada, Mexico, Australia and New Zealand. According to EE, this covers over 80% of time EE customers spend overseas.

O2 customers get inclusive roaming in 47 European destinations. And if you’re travelling further afield, you can buy a travel add-on, so you can use your phone without worrying about running up a huge bill.

Vodafone customers can use their monthly allowance of calls, texts and data from 50 European countries at no extra cost. Vodafone's Roam Further allows you to use your monthly allowance for an additional £5 per day in 60 countries outside the EU, including the United States, Canada, Australia and China.

If you want to find out more before you fly, check out our complete guide to data roaming.

How much does it cost if you go over your mobile phone internet limit?

Woman holding phone

Most networks will now warn you when you’re about to go over your data limit, allowing you to purchase add–ons rather than paying per MB. If this keeps happening, be sure you upgrade your deal, as it’s cheaper than constantly paying out.

SIM-only contracts make it easier to do this. Also, networks like Smarty and VOXI allow you to easily tweak your data allowance every month depending on your needs and usage.

How much it's likely to cost you for going over your allotted mobile phone internet limit varies, depending on which tariff you have chosen and which network you are with.

However, in some cases it gets very expensive when you exceed your mobile data limit. So it’s important to find a tariff that matches your needs.

What is a fair use policy?

Overcharged hero size

Some mobile networks simply limit your internet usage rather than charge extra when you exceed the data you've paid for. This is called a 'fair use' policy.

It means that you may not incur an extra charge when you use up your monthly allowance, but you may be penalised if you go over by what the network decides is 'fair'- often around 500MB.

But that's not all. Some networks that favour fair usage policies will reduce your internet speed until your monthly allowance renews, so you will not be able to stream long videos or download large applications.

It’s worth contacting your network and asking them to explain this policy fully. That way you can either change deals or at least get to grips with how much data you’re using each month and work out how to moderate it.

What about 5G data services?


5G is the next big thing in mobile, delivering speeds that exceed home broadband.

5G is considerably faster than 4G, and while this means that you'll be able to download entire HD movies in seconds, be aware that this will use up a lot of data.

Luckily, some networks have changed their plans a bit to accommodate 5G. For instance Vodafone's Unlimited plans work more like a broadband plan - you get unlimited data as standard but the price plans are varied by speed.

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