Lost mobile number? Here is how to block your SIM card to prevent misuse
Jakarta (ANTARA) - Losing a mobile phone or SIM card must be addressed immediately to prevent phone numbers from being misused for fraud, account hijacking, or unauthorised access to digital banking services. One of the first recommended steps is to immediately block the number through the mobile operator being used.
Phone numbers are now linked to various essential services, ranging from social media and digital wallets to mobile banking. Therefore, number blocking should be performed as soon as a phone or SIM card is declared lost to minimise the risk of personal data misuse.
Here is how to block a lost mobile number quickly and practically:
- Contact the operator’s customer service
The first step is to contact the call centre of the mobile operator used, such as Telkomsel, Indosat, XL Axiata, Tri, or Smartfren. Inform the agent that your number is lost and request a temporary or permanent block. Usually, the agent will perform identity verification, such as checking the National Identity Number (NIK), Family Card (KK) number, or other data used during the SIM card registration.
- Visit an official operator outlet
If customer service cannot be reached, users can visit the nearest official operator outlet, bringing an identity card such as a KTP (National ID). At the outlet, customers can request a number block and simultaneously apply for a SIM card replacement to continue using the old number.
To expedite the process, prepare the following documents:
KTP (National ID).
Family Card (KK) number, if required.
The lost phone number.
Information regarding the last top-up or other registration data if requested by the operator.
These documents are used to ensure that the applicant is the legitimate owner of the phone number.
- Secure digital accounts
In addition to blocking the number, immediately change the passwords of accounts linked to that number, such as:
Email.
Mobile banking.
Digital wallets.
Social media.
Instant messaging applications.
If available, activate two-factor authentication (2FA) using other devices or methods to keep accounts secure.
- Use device tracking features
For both Android and iPhone users, utilise device tracking features such as Find My Device or Find My iPhone to locate the phone, lock the device remotely, or wipe data if necessary. This step can help protect personal information if the phone cannot be found.
If the phone is suspected to have been stolen, immediately report the incident to the police. A police report can serve as supporting documentation for processes with the operator or for other administrative purposes.
Does the IMEI also need to be blocked?
The government, through the Ministry of Communication and Digital (Komdigi), is strengthening device protection systems through the International Mobile Equipment Identity (IMEI). The IMEI serves as a unique identity for the device and can support protection if a phone is lost or stolen. However, when a mobile number is lost, the fastest step to take is to block the SIM card through the operator so the number cannot be used by irresponsible parties.
Tips to prevent number misuse
To reduce the risk of phone number misuse, the public can implement the following steps:
Block the SIM card immediately after the phone is lost.
Never share OTP (One-Time Password) codes with anyone.
Use a PIN or biometrics on the SIM card and phone.
Activate two-factor authentication on important accounts.
Regularly update digital account passwords.
By taking these steps as soon as possible, the risk of misuse of phone numbers and personal data can be minimised.