The hype around new mobile phone launches means many smartphone manufacturers are presenting new models more frequently, some with more advanced technical specifications, but many with a few cosmetic changes. Because of this constant stream of new smartphones and tablets, and the pressure of having the latest technology, many people are replacing their devices annually. Something that many people take for granted is the sheer volume of personal information stored within our devices. As such, when selling or giving away an old device, it’s important to make sure none of this data can be acquired.

The market for second hand smartphones and tablets is huge, and many shops will buy them or offer trade-in deals to get a discount on the latest device. In 2015, Garner estimated that 56 million second hand smartphones were sold the previous year – an equivalent wholesale revenue of $7 billion. By 2017, this is expected to rise to 120 million units, with a wholesale revenue of $14 billion. With this constant exchanging of smartphones, data is protection is paramount. All manner of data is stored on our smartphones, which in the wrong hands, could be a huge problem. Without securely erasing the new owner will be able to access your photos, contacts, emails, SMS messages and potentially even credit/debit card details saved in apps.

Data is stored on smartphones on the SIM card, external memory, and internal memory. The SIM card typically stores basic elements that take up little space, like text messages and contacts. The rest of the data – photos, videos, documents, emails etc – is stored on internal and/or external flash memory. Most phones have the ability to add to the internal storage with micro SD cards, with the notable exception to this being the iPhone.

One effective way to erase data from the internal memory in smartphones is the factory reset option. This feature is designed to restore the device to its original conditions, as if it were taken out of the box. In many cases, however, it is still possible for an expert to recover data from a reset device. For peace of mind, it is worth investing in a piece of software that can securely erase all data, such as Blancco Mobile Device Eraser. With SD cards, you should format them if you are going to include it at all; many people choose to keep hold of them. With SIM cards, you should remove and keep these as they contain personal information unique to you, like your number.