The BBC's recent investigation highlighting how easy it was to sell, and therefore buy, a stolen phone is quite alarming. According to the UK's National Mobile Phone Crime Unit, between 250,000 and 300,000 mobile phones are stolen in the country every year and, by the looks of the investigation, the people that steal them have no problem making a buck from your misfortune.

While no one intentionally loses their phone or has it stolen, avoiding it is sometimes more than common sense so we have rounded up a few tips to prevent it, along with a few ways to check if a phone you are buying was stolen from someone else.

READ: BBC investigation reveals how easy it is to sell a stolen phone

Common sense

The most obvious trick to preventing your phone being stolen is to keep it in sight at all times, but even that isn't always enough.

If it's in a pocket, then a front pocket is of course better and if it is in your bag, then make sure it is in a zipped up section and that you keep your bag within reach or where you can see it. Also, Police advise that you avoid waving it around when in the street. You might want to check your emails or the internet, but holding it out in one hand makes it an easier target.

Directly outside London Tube stations are troublespots for phone theft as many travellers often immediately check their messages as soon as they leave the Underground.

You should make a note of all your phone's information, which you can find on the box it comes in. Write down your number, the make and model of the device, its colour and what it looks like, your lock code and the IMEI number. Once you have all of these, you can report it easily if it is stolen.

Adding a security mark, such as your postcode, with an ultraviolet pen is also a good idea as it makes the device more easily identifiable if something happens to it.

Set up a PIN

Typing in a PIN every time you need to unlock your phone can be a little frustrating, but it will make your phone less valuable to thieves and they won't be able to access what you have stored on your SIM card easily.

Whether you have an iPhone, Android, Windows Phone or BlackBerry device, they all have the capacity to set up a PIN or lock code so make sure it is one of the first things you do when you get a new phone. With some modern phones, such as the iPhone 5S and Samsung Galaxy S5, you can also lock your phone using your fingerprint.

Download a tracking app

Downloading a tracking app should also be high on your priority list when you get a new phone, or after reading this feature.

It doesn't matter if you have the latest Samsung Galaxy S5 or a HTC from three years ago, if you lose your phone, there is bound to be some information on it that you don't want getting into the wrong hands.

There are a number of apps such as Andorid Lost, Android Device Manager and Find my iPhone that will not only help you track your device, but also wipe it if it does get stolen.

The Android Lost app for example, will let you remotely read sent and received SMS messages, wipe your phone, lock your phone, erase the SD card and locate the phone by GPS or network.

Android Device Manager on the other hand will help you locate a device that is associated with your Google account and enable you to reset your lock code or erase all the data on it.

For iPhone users, Find my iPhone will allow you to use another iOS device to show you where your phone is on a map, after which you will be able to protect your data by remotely locking it or deleting everything on it.

Windows Phone users can go to the My Phone section of the Windows Phone website where you will be able to ring, lock, erase or show your phone on a map from any internet-connected computer.

Finally, BlackBerry users can download BlackBerry Protect that will help you find your device and keep the information on it secure. If your phone is stolen, you can log in to the BlackBerry Protect website and lock your device, as well as delete the information on the phone itself and the microSD card.

Contact your network carrier

It's worth registering your device with your network operator if the option is there but aside from that, if your phone is lost or stolen, then report it to them immediately.

They should be able to block your phone and your account details so the phone won't be able to be used across any network even if the SIM is changed.

It's also an idea to make sure you have your phone number disabled at the same time so that no further calls or charges can be made. If your phone is stolen, inform the police straight away as this will ensure you have evidence if your network provider or insurance company needs it.

Check before you buy

If you are in the market for a new phone but you want to check whether the deal you are getting is too good to be true, you need to get hold of the IMEI number before you buy.

If a phone is blocked, it will either power up and you'll get no signal, or it will look as though it is working properly but reject calls when you try to use it. Either way, the phone is useless to you if it doesn't work.

The IMEI number can sometimes be found on the device itself - under the battery, for example - or you might need to dial *#06# (star, hash, zero, six, hash) on the keypad and press call to get the 15-digit number to appear.

Once you have the number, you can check whether it is stolen by visiting a number of websites such as CheckMEND. There are a couple of free sites too as CheckMEND will charge you £1.99, but it does offer you a full report on the device's background history, which could be more useful than you think. It's better to be safe than sorry as they say.