Does your iPhone (or iPad) keep running out of cellular data before your allowance is reset each month? Do you feel like your cap is too restrictive, but can't afford to upgrade to a more generous iPhone contract?

If you're tired of running out of data every month, follow our tips and never hit your limit again.

Wi-Fi Assist

Wi-Fi Assist

A quick one worth checking before we move on to more difficult or inconvenient solutions.

When Apple introduced iOS 9 some users found that their Mobile Data (or Cellular Data if you are in the US') was being gobbled up more rapidly than before. It turned out that the reason for this was Apple's new Wi-Fi Assist feature, which switches to the mobile network if your Wi-Fi is flaky - often handy, but likely to increase your data consumption.

If you think this is happening to you, you can turn this feature off in Settings > Mobile Data then scroll to the bottom of the page where you can turn off Wi-Fi Assist.

In iOS 10 or later, the feature shows how much data has been used by Wi-Fi assist. It's still a feature that's on by default, though.

Apple has at least made sure that there are some limitations to the feature. It won't work when you are using data roaming in another country, and not all apps can access the feature; for example, video and audio streaming apps are exempt. However, Apple's Safari, Mail, Maps and Apple Music do use the feature.

Track how much iPhone data you use

Track how much iPhone data you use

Before you can start to manage your iPhone cellular data usage, you need to keep tabs on how much you're using. To view how much data you've used, go to Settings > Cellular (or Mobile Data) and scroll down to see your mobile data usage for the current period. Below this you'll see how much data has been used by each app.

Our advice is to get in the habit of resetting it every month; perhaps set an alert on your phone so you remember to reset it on the day your network resets your allowance. To reset your statistics, scroll down to the bottom of the page and tap Reset Statistics. Get in the habit of looking here once in a while so you can see if you're on target to stay under the limit, or if you're overdoing it and need to rein things in.

Those looking for something a little more comprehensive should take a look at Data Usage (49p/99c), an app that we've used for the past three years to keep track of our monthly data usage.

The app looks to measure cellular and Wi-Fi data usage in real time, and offers this in two different ways - via the app itself, and via a handy Today widget that can be added to your notification centre.

The app asks you to input your monthly data limit and then produces statistics like how much you should use per day until your data is renewed, or if you're likely to go over your allowance in any given month.

Users can also take a look back at the data from any month in the past, as long as the app was being used then, of course.

Stop iPhone apps using cellular data

Stop iPhone apps using cellular data

Back in iOS 7, Apple introduced the ability to determine which apps on your iPhone are allowed to use cellular data.

When we are close to our allowance, we head to Settings > Cellular/Mobile Data and scroll down to switch off a number of apps' cellular privileges.

The other benefit of stopping some of your apps using cellular data is that it should stop them updating in the background when you're out and about - thereby improving battery life.

Below each of the apps on the Settings > Cellular page you will see just how much data they have been using. Any that stand out as guzzling a lot more data that you think they should be can be switched off here.

Turn off 3G and 4G data on your iPhone

Turn off 3G and 4G data on your iPhone

If things are really desperate, one way to preserve your data when you're running low is to temporarily disable cellular data. This way if you have a week or so to go until your contract renews you can manage your usage rather than running out completely.

To turn off your cellular data go to Settings > Mobile Data (or Cellular Data) and toggle the Mobile/Cellular Data switch to off.

This will turn off all cellular data and restrict all data to Wi-Fi, including email, web browsing and push notifications. We also find this is a handy way to preserve battery life - as opposed to switching on Airplane Mode, which preserves power but means nobody can contact you.

Turn off autoplay video in Facebook, Twitter & Instagram

Turn off autoplay video in Facebook, Twitter & Instagram

A while ago Facebook added a feature to their iOS app that means when you're scrolling through your news feed any video that's been posted will automatically stream - even if you're not on a Wi-Fi network. Obviously this isn't an ideal situation if you've got a limited data allowance.

We recommend you change your settings so that it only streams if you're on Wi-Fi.

Open Facebook and click on More at the bottom of the screen. Now choose Account Settings > Videos and Photos > Video Settings > Auto-play and select On Wi-Fi Connections Only or Never Auto-plays Videos.

Like Facebook, Twitter has an autoplay video feature that you can turn off in the app. Tap your avatar image in the top left to display your profile details, then hit Settings and privacy > Data usage. Tap the 'Video autoplay' entry and change it to 'Only on Wi-Fi'.

A better policy, however, may be to simply hit the Data Saver toggle at the top of the Data Usage page - this turns off autoplay and lowers image quality too.

There is a similar series of steps in Instagram to turn off video streaming over your data connection. Tap the Gear icon in Instagram, select Mobile Data Use and choose the Use Less Data option.

Stop using data-hungry apps on 3G or 4G

Stop using data-hungry apps on 3G or 4G

FaceTime: It's great that we can use FaceTime over 3G or 4G, but it sucks up data. Go to Settings > Cellular/Mobile Data and scroll down your list of apps to make sure FaceTime is switched off for cellular data. Crucially, this will also stop anyone contacting you via FaceTime over 3G.

iCloud Drive: Go to Settings and tap your name/picture at the top, then tap iCloud. Scroll down and tap the toggle next to iCloud Drive so it turns white - or off. Your iPhone will only update iCloud Drive when you're on a WiFi network. Alternatively, turn off the ability for apps to store documents and data in the cloud by toggling the switch beside each app to off.

iTunes: Go to Settings > iTunes & App Store and make sure that Use Cellular Data/Mobile Data is switched off. Similarly, if you're an Apple Music subscriber, make sure Mobile Data is not selected in Settings > Music.

Use Safari reading list to view articles offline

Use Safari reading list to view articles offline

Safari's Reading List feature lets you download a web page for reading offline. This is great when you're reading an article during a commute and about to head into a tunnel.

It's also great if you are out of data: you can queue up a few web pages in your Reading List while you're on Wi-Fi, then read them without using up any data.

While you have access to Wi-Fi go to Safari, open the web pages you wish to read, click on the Share icon at the bottom of the page and select Add to Reading List. Wait for the phone to download the article and then head out.  You will be able to read this article even if you're using Airplane Mode.

Turn off Push Notifications

Turn off Push Notifications

How many of your applications are using the Apple Push Notifications service to alert you to new data?

Go to Settings > Notifications to find out. You can easily stop any apps from pestering you with Notifications here.

The format for this has changed slightly in iOS 9 and iOS 10. Previously you could scroll down the list, tap on those apps you don't want to notify you, and toggle to switch beside: Show in Notification Centre, and Show on Lock Screen.

However, you would still want to make sure that those apps that you still want to receive notifications for aren't doing so over your cellular connection.

In iOS 9 you get the choice of notification style for each app. You can choose for apps to not Allow Notifications. Or you can choose the kind of Notifications you allow.

It's slightly annoying that you have to turn off Notifications on a per app basis, but you can at least see the kind of notification setting you have for each app without tapping on them first (it's below the name of the app).

Note that if you have an Apple Watch you may want some apps to display notifications on that device - go to the Apple Watch app to set this up. 

Those apps that appear under Include on the Notifications Centre tab may be using data to alert you to changes. If you really don't need to be told that your friend has replied to your post on Facebook turn Notification Centre off by tapping Facebook, and switching the slider to off.

Be ruthless with the apps that are alerting you to changes, although if you then end up checking them every five minutes it may be a false economy.

Stop fetching email

Stop fetching email

Another one to curb is your email. If you have the phone or iPad set to fetch data wirelessly at specific intervals you will quickly consume data – this can get really out of hand if you have your iPhone set to Push data to your iPhone from the server as it will be updating all the time.

Start by making sure that Push is not selected. The way of doing this has changed in iOS 10.

Previously you could go to Settings > Mail, Contacts, Calendars > Fetch New Data and if Push is turned on, turn it off.

Then to make sure you are set to fetch data manually. Go to Settings > Mail, Contacts, Calendars > Fetch New Data and scroll down and select Manually from the list. You can be even more precise if you prefer, and amend your fetch settings for separate accounts. Changing these settings also has the benefit of preserving battery life.

In iOS 10 you need to got Settings > Mail > Accounts > Fetch New Data and from that screen change Contacts & Calendars, and iCloud to Fetch and then in the list below set Fetch to Manually.

In iOS 10 there are some additional ways in which you can cut back on Mail's data usage.

In Settings > Mail scroll to the Messages section and deselect Load Remote Images.

Stop background app refresh

Stop background app refresh

Your iPhone or iPad can automatically update its operating system and apps in the background without you having to act. This saves time and hassle.

However, this can cause a problem if your phone decides to update when you're not on a Wi-Fi network. Head to Settings > General > Background App Refresh and tap Background App Refresh at the top. Select Wi-Fi (as opposed to Wi-Fi & Mobile Data) to limit this feature's activities.

Browse in Chrome

Browse in Chrome

There are alternatives to Apple's Safari when browsing the web on the iPhone and iPad, and a good one to try out if you're a bit short of data is Chrome.

The Chrome app has a Reduce Data feature that will go some way to reduce the size of the websites you are browsing by running the site through Google's servers and compressing the data. For a deeper look at your options, read Best web browsers for iPhone.

Low-res images in Messages

Low-res images in Messages

In iOS 10 or later, you can choose to send low-quality images in Messages. Instead of sending an image in high resolution it will automatically send it as a compressed version, thereby saving your data.

To do so, go to Settings > Messages and turn on Low-Quality Image Mode, which you'll find at the very bottom of the settings list.

Mind what you watch on cellular

Mind what you watch on cellular

Whether it's Netflix, YouTube or iPlayer, watching your favourite shows could eat up your data if you watch over 3G/4G. In each app, go to Settings and select to play back only over Wi-Fi.

For example, in YouTube go to Settings and choose Play HD on Wi-Fi only. In Netflix, go to App Settings > Cellular data usage.

Keep Wi-Fi on

Keep Wi-Fi on

If you've ever found yourself switching off Wi-Fi entirely because your phone keeps trying to connect to a network when you're in town, you may find yourself using cellular when you get back home.

It's a frustration that's easily fixed if you choose to forget the network when one of them pops up.

Just tap on the network name, and in the following screen select Forget this Network.

Use Wi-Fi hotspots

Use Wi-Fi hotspots

You'll be able to find Wi-Fi networks all around, especially in any big city. You can find Wi-Fi in most coffee shop chains, many restaurants, and other public areas like libraries and airports. If you are a BT broadband subscriber you can use the BT Wi-fi app to get on to any of their hotspots for free.

However, you should always exercise an air of caution when accessing a hotspot, as we explain in this article: How do I know if a Wi-Fi hotspot is safe?. The best advice is to use a Wi-Fi hotspot that requires a password - it's an extra assurance that someone else won't be spying on what you're doing.