Data deletion guide: how to prevent your personal data from falling into the wrong hands

Happy holiday photos, last month’s gas meter reading, credit card details, text messages – people store a lot of similar, often sensitive data on their mobile phones, often without realising it. According to a recent survey, a significant proportion of Hungarians pass on their mobile phones to others, and many of them do not delete the data stored on them, which could fall into the wrong hands. Yettel can help you keep your data safe and you can even get a discount, if you return your old phone to the operator.

According to a recent nationwide survey by Yettel[1], 40% of Hungarians give away or donate their old mobile phones, and 23% sell them. But what happens to the data left on the old phone? While 65% of respondents fear that their data could be misused, 16% have not deleted their personal data before giving their old mobile phone to someone else. In addition, 14% would not do anything with the content on their mobile phone themselves, but would ask others to help.

But people store a lot of personal and sensitive information on their handsets, from photos of themselves and others, to bank card details and passwords or their social media accounts. If your mobile phone falls into the wrong hands, all this information can be misused. Typical types of fraud include impersonation, where money or information is obtained using your name and details. To avoid this, it’s worth following a few simple steps before you give your handset to someone else. But even if you forget to delete your data, all is not necessarily lost.

What to do if you want to remove your data

First, back up all the data on your phone so you can access it later. Many phones store some data in the cloud – iCloud for iPhone, Google account for Android or in the vendor’s profile. It makes sense to set up regular automatic backups, but before you give your phone to someone else, you should back it up manually. There are also apps designed specifically to help you transfer data when switching between mobile operating systems. If your device has an SD card, remove it, as it can also store personal data.

Then start the factory reset process, which will remove all your data and custom settings from your phone and restore factory settings. It’s better to choose this option than delete your data manually, because it ensures that no sensitive information – such as your browsing history, passwords, bank details, messages and company correspondence, as well as stored images and videos – remains on your phone.

The process for restoring factory settings also varies depending on your phone the. For iOS, it can be found in the “Settings > General” menu under “Transfer or Reset iPhone”. For Android, it depends on the vendor, but in most cases you can access the “Factory Reset” option in “Settings > General Management > Reset”.

If data remain on the handset

If you receive a second-hand phone from a family member or friend, it may still have the previous owner’s data on it. In this case, ask them whether they need a backup and then restore the factory settings. You may not be able to do this because the previous user set a password, so it’s important to delete all data before you give away your phone to someone else.

All is not lost if your data remains on a phone that has been given away. If you are still signed in to your online account on the handset (iCloud for iOS or Google Account for Android) you can remotely lock or delete the account from the phone using the web interface of these services. This option is also useful if your phone is lost or stolen.

Help with permanent deletion

In addition to the above, the National Media and Infocommunications Authority (NMHH) also offers a service that irreversibly deletes the data stored on your smartphone. When you buy a new handset, you get a data erasure code that you can use to start the erasure process at You can find more information about the service on Yettel’s website.

If you’re done with the factory reset and can’t give your old phone to anyone else, why not bring it to a Yettel shop where your operator will make sure it’s recycled professionally? Now you can even get a substantial discount for doing so. If you return your old mobile phone – even if it doesn’t work anymore – to Yettel by 30 August, you receive a discount of HUF 30,000 on a new mobile phone with a public consumer voice tariff and a 2-year contract.

More information:

[1] A nationwide survey commissioned by Yettel and conducted on the Ipsos online panel, representative of gender, age, type of settlement and region, completed by 840 respondents between 30 June 2023 and 6 July 2023.