Skip to main content
Privacy Protection

What to Do First When You Lose Your Smartphone

About 12 min read

Stay Calm and Work Through the Steps in Order

Losing your smartphone makes your mind go blank, but the things you need to do are fixed. Work through them in order and you will be fine. Acting in a panic can actually make the situation worse. Take a deep breath, then go through the steps below one at a time.

A smartphone holds an enormous amount of personal information - your phone number, contacts, social media accounts, photos, email, electronic money. Moving quickly matters because it stops whoever picks up the phone from reaching any of it. Learn these steps to protect your phone number privacy. It also pays to think about keeping the contacts on your phone safe as a matter of daily habit.

Step 1: Locate the Phone

First, check the location of your phone from another device - a friend's phone, a computer, anything to hand.

  • iPhone: sign in at iCloud.com, choose "Find", then select the device
  • Android: sign in at google.com/android/find, then select the device

The location appears on a map. If the phone is nearby you can also make it play a sound to find it. Even with silent mode switched on, the sound triggered from the Find feature plays at full volume.

If the location is shown as "the place it was last online", the phone may be out of battery or somewhere without a signal. In that case, use the last known location as a clue and search the places you think you may have been.

Step 2: Lock the Phone Remotely

If you cannot find the phone, lock it remotely. That stops whoever picks it up from seeing what is inside.

  • iPhone: "Find", turn on "Mark As Lost", then enter a contact phone number
  • Android: "Find My Device", "Secure device", then show a message on the lock screen

You can display a phone number on the lock screen with a note asking the finder to get in touch. Set that number to a family member or a friend rather than your own - your own phone is not in your hands.

Step 3: Call Your Carrier and Suspend the Line

If the phone does not turn up, call your carrier and suspend the line temporarily. That prevents anyone from making calls or sending SMS with your number. Suspending the line also removes the risk of someone pulling out the SIM card and using it in a different handset.

  • NTT Docomo: 0120-524-360 (24 hours)
  • au: 0077-7-113 (24 hours)
  • SoftBank: 0800-919-0113 (24 hours)
  • Rakuten Mobile: 0800-600-0500 (24 hours)

A suspension can be lifted if the phone comes back. While it is in place you lose calls and mobile data, but the Find feature still works wherever there is Wi-Fi. As explained in our guide to handling calls from withheld numbers, it is reassuring to know in advance how to react to a suspicious call that arrives while the line is suspended.

Step 4: Change Your Passwords

Change the passwords for the services stored on the phone, starting with the highest priority.

  1. Google account / Apple ID: if one of these is taken over, the damage spreads across email, cloud data, purchase history and much more
  2. LINE: sign in from another device and check the account transfer setting. Change the password and look for any sign-in you do not recognise
  3. Social media (Instagram, X and so on): change the password and sign out of every active session
  4. Online banking and electronic money: change the passwords for banking apps and mobile payment services such as PayPay and Suica, then check the transaction history for unauthorised use

While you are changing passwords, review your two-factor authentication settings too. Any service that uses SMS verification cannot deliver a code while the line is suspended. If you use an authenticator app such as Google Authenticator, you can sign in with your backup codes.

Step 5: Report the Loss to the Police

File a lost property report at your nearest police box or police station. Once the report is on file, you will be contacted if someone hands the phone in.

A lost property report needs the following details.

  • The date, time and place where you lost it
  • The model name and colour of the phone
  • The phone number
  • Anything distinctive about how it looks, such as the case

Some stations will accept a lost property report over the phone. Ask the station nearest to you.

Step 6: Suspend Electronic Money

If you had electronic money or mobile payments set up on the phone, go through the suspension procedure for each of them to prevent unauthorised use.

  • Mobile Suica / PASMO: apply for suspension through the service's website or call centre
  • PayPay, Rakuten Pay and similar: sign in from the website and suspend the account
  • Credit cards (Apple Pay / Google Pay): call the card issuer and ask for the card to be suspended

Preparations Worth Making Now

To keep the damage from a lost phone to a minimum, get the following in place while you still have the phone.

  • Always set a screen lock (passcode, fingerprint or face recognition): this is the most basic defence of all. A passcode of six or more digits, or biometrics, is safer than four digits
  • Turn on the Find feature: on iPhone go to Settings, your name, then Find My; on Android go to Settings, Security, then Find My Device
  • Set a PIN code on the SIM card: this stops the SIM being removed and used in another handset. The initial PIN is often set to 0000 or 1234, so be sure to change it
  • Back up important data to the cloud: with photos, contacts and notes saved in the cloud, losing the phone does not mean losing the data
  • Write down emergency contact numbers: keeping your carrier's loss reporting number on paper or on another device saves you from panicking when the time comes

Summary

If you lose your phone, work in this order: locate it, lock it, suspend the line, change your passwords, report it to the police, then suspend electronic money. The best preparation is to keep a screen lock and the Find feature switched on at all times. Do not forget to set a PIN code on the SIM card as well. Keeping phone number privacy in mind day to day is what keeps the damage small if the worst happens.

XHatena

Was this article helpful?

Frequently Asked Questions

Can I still use LINE if I suspend my phone line?

Suspending the line stops calls and SMS, but LINE messages may be accessible via Wi-Fi on another device. Prioritize changing your LINE password to prevent account hijacking.

What if I didn't have a screen lock set?

Immediately contact your carrier to suspend the line and change your Google/Apple ID password. Even without remote lock, you can remotely erase (factory reset) the device.

What should I do after finding my lost phone?

First, contact your carrier to reactivate the line. Then check for any unfamiliar apps and change your passwords again as a precaution. If there are signs the phone was tampered with, run a security scan or consider a factory reset.

Search a Phone Number

Received a call from an unknown number? Search the phone number to check caller information and reviews.

Search Phone Number