Have you ever wondered what happens to your personal data when you sell or throw away an old smartphone? In this age of digital threats and information leaks, even such a seemingly simple step can have unpleasant consequences. No wonder millions of people google how to track a phone number every month – no one wants to be in a situation where someone gets access to their contacts, correspondence or banking applications.
Today, security is not just about passwords. Even a seemingly useful and innocuous app like Number Tracker, which helps you track the location of your loved ones, contains information that you hardly want to hand over to the wrong hands. That’s why it pays to go through a competent data protection checklist before handing over your smartphone to a new owner – whether it’s a sale, exchange or gift. So, today you will learn how to do it right and quietly let go of your old device without risk to yourself.
Preparation — Before Factory Reset
Before you even consider wiping your device, this checklist will help you secure your digital life and avoid leaving a trace behind:
- Back Up All Your Important Data
Before anything else, back up everything — and we mean everything. Use Google Drive, iCloud, or Samsung Cloud depending on your operating system. Make sure to manually check that photos, videos, contacts, calendar events, and notes are properly synced. One of the most overlooked categories? Chat histories.
Apps like WhatsApp or Telegram allow you to back up conversations to the cloud. If you skip this step, those memories and messages could be gone forever. And if you are a media-heavy user, it also will be smart for you to enable automatic uploads of images and videos through services like Google Photos or iCloud Photos – that way, nothing gets left behind.
Lifehack: For extra security, consider creating an encrypted local backup on your computer using iTunes (for iPhones) or Smart Switch (for Samsung devices).
- Sign Out of All Accounts
Signing out may sound simple, but many apps retain data in the background if not manually logged out. Be thorough:
- Google account
- Apple ID
- Social media platforms (Facebook, Instagram, TikTok, etc.)
Banking and shopping apps
Here is an important point many miss: disable any tracking or recovery features before the reset. For Apple users, this means turning off Find My iPhone. For Android users, disable Find My Device. Failing to do this could result in the phone being locked after resale – and that is not just inconvenient, it is a great security risk [personally for the previous owner.
- Unlink Phone Numbers from Security Settings
These days, your phone number is more than a contact – it is like a verification token. Today many apps and services use SMS-based Two-Factor Authentication (2FA), which can leave your accounts vulnerable if someone else gains access to your old SIM card or phone.
Thus, before you will reset the device, go into each service’s security settings and remove or update your linked number. For long-term security, move your 2FA to an authentication app like Google Authenticator, Authy, or Microsoft Authenticator. This way, even if your number is reused or stolen, your accounts remain protected.
Interesting fact: According to Google’s own security blog, adding 2FA can block up to 100% of automated bot attacks and 96% of phishing attempts. But it works only if it is set up properly before the device changes.
Data Cleaning — Erasing It the Right Way
After prepping your phone and securing your accounts, it’s time to get serious about cleaning house. Many users think a factory reset is the final step, but actually this is only part of the equation. If you do this carelessly, traces of your personal data can still be recovered by tech-savvy people with even some simple or basic recovery tools.
In 2022, researchers at the University of Hertfordshire found that over 50% of second-hand phones still contained retrievable personal information, including photos, emails, and even sensitive documents. So, not let us make sure your old phone doesn’t become part of that statistic.
- Manually Delete All Files
Factory resets are great, but they don’t always clean out the corners, especially when it comes to your download folders, cached files, or offline app data. So you need to delete all these data manually and here you can start by going through your:
- Downloads folder (especially on Android devices)
- Cloud-synced apps – make sure nothing is saved locally
Browsers (clear history, cache, saved passwords, and autofill data)
If you are switching from Android, check folders like DCIM, Bluetooth, and Screenshots. For iPhones, make sure deleted photos are also cleared from the Recently Deleted album – they linger for up to 30 days otherwise.
Lifehack: Use a free file manager app like Files by Google or iExplorer to dig into hidden folders that traditional file views may miss.
- Perform a Full Factory Reset
Now that you’ve scrubbed the surface, it’s time for a clean slate. The process differs slightly depending on your device:
- iOS: Go to Settings > General > Transfer or Reset iPhone > Erase All Content and Settings.
- Android: Navigate to Settings > System > Reset > Factory Data Reset.
Don’t forget to charge your phone – a failed reset due to low battery could corrupt the wipe process. This step will remove all user data, accounts, apps, and settings. But it still doesn’t mean your phone is impenetrable.
Post-Wipe Security Check: Don’t Let Digital Traces Follow You
So, now your phone is backed up, wiped, and encrypted. Job done? Not quite. The real question is – what does your old device still know about you even after it is “clean”? Many users don’t realize that simply resetting a phone doesn’t sever all digital links. That’s where the post-wipe security check comes in, i,e, it is a final but crucial step to reclaim your privacy and close every open door.
- Change All Major Passwords
Resetting your old passwords is one of the most fundamental steps you can take to secure your digital life. Focus first on accounts that store or handle sensitive information: your email accounts, banking apps, social networks, cloud storage platforms, and any e-commerce sites you regularly use. These are the gateways to your identity, and they’re often where attackers strike first.
Why do it now? Because old credentials might still be lingering in your device’s memory — stored in browser autofill systems, within app data, or synced across devices. By updating your passwords before handing over your phone, you sever that digital connection and ensure that any locally saved credentials become completely useless to whoever might access the device later.
Bonus Tip: Use this moment to activate two-factor authentication (2FA) if you haven’t already. It’s one of the most effective barriers against account theft.
- Recheck Location Sharing and App Access
Many people don’t realize that certain apps retain location-sharing permissions even after a reset — especially security or utility apps. These permissions may remain active if synced through cloud backups or associated with your account. Thus, you need to review and adjust app-level location settings before and after resetting your phone. How to do it:
- Log into your Google or Apple account on a desktop or another device.
- Open the privacy or security dashboard, typically found under account settings.
- Review the list of apps that are connected to your account – especially those with location access or background permissions.
- Revoke access or disable permissions for any app you no longer use or trust.
And if you are giving the phone to someone else, ensure no app is still sharing your location or pulling background data – it is an easy step to overlook, but vital for privacy.
Leave the Phone, but not the Data
Your smartphone may leave your pocket, but it shouldn’t take a byte of unnecessary information with it. Technology changes, but good digital habits remain. Checking settings and paying a little more attention today – and no “surprise” tomorrow. So take the process of cleaning your phone carefully, because it is better to leave an old phone a good memory than to accidentally give it a new life… with your secrets.