High riskText Message Scams

SIM Swap Scam

In a SIM swap scam, a fraudster persuades your mobile carrier to move your number to their SIM, then intercepts your calls and one-time codes to break into your accounts.

Quick verdict

Risk level
High risk
Scam type
Account takeover scam
Main red flag
Your phone suddenly loses signal or service for no clear reason, especially after you shared personal details.
What to do first
Contact your mobile carrier immediately using another phone to check whether your number has been transferred.

What this scam usually looks like

In a SIM swap scam, a fraudster persuades your mobile carrier to move your number to their SIM, then intercepts your calls and one-time codes to break into your accounts.

Example message pattern

Example pattern — not a real report
Example pattern: 'Your SIM transfer request has been received and your new SIM will activate shortly. If this was not you, call us at [unfamiliar link].'

This is a fictional, anonymised example used to illustrate the pattern. It is not a verified real message, and any names are used only to show how the scam typically reads.

Red flags to watch for

  • Your phone unexpectedly loses signal or shows 'No Service' with no outage in your area
  • Texts or calls stop arriving even though your phone seems on
  • Notifications that a new SIM or eSIM was requested on your account
  • Being locked out of email, banking, or social accounts soon after losing signal
  • Earlier phishing messages asking for your name, date of birth, or account details

What to do

  • Contact your mobile carrier right away from another phone to report and reverse the swap
  • Add a security PIN or passcode to your mobile carrier account to block future swaps
  • Secure your email and banking accounts and change their passwords from a trusted device
  • Where possible, switch important accounts from text codes to an authenticator app

If you already clicked or replied

  • Assume your password may be known and change it from a device you trust
  • Review your bank and email accounts for any unfamiliar logins or changes
  • Turn on app-based two-factor authentication instead of text codes where available
  • Report the incident to your bank and your national anti-fraud centre

What not to do

  • Do not ignore a sudden, unexplained loss of phone service
  • Do not rely only on text-message codes for your most important accounts
  • Do not share account PINs or verification details with anyone who contacts you

Similar scams

High risk Text Message

Two-Factor Code Text Scam

In this scam a fraudster triggers a genuine two-factor or one-time code to your phone, then poses as support staff or a contact to pressure you into reading it back so they can take over your account.
High risk Marketplace

Google Voice Verification Code Scam

On a marketplace, a supposed buyer or seller asks you to share a verification code texted to your phone to 'prove you are real'. The code is actually used to set up a Google Voice number linked to you, which the scammer then uses for further fraud.
High risk Bank & Payment

Fake Bank Alert Text Scam

This scam sends a text claiming suspicious activity on your account, then steers you to a fake login page or a 'fraud agent' who pressures you to move money.

Frequently asked questions

How does a SIM swap actually work?
A fraudster gathers your details, often through phishing, then contacts your carrier pretending to be you and asks to move your number to a new SIM. Once it activates, your calls and codes go to them.
Why is losing signal a warning sign?
When your number is moved to another SIM, your own phone usually loses service. A sudden, unexplained 'No Service' message, with no local outage, can be an early sign of a swap.
How can a PIN on my carrier account help?
Many carriers let you set a separate PIN or passcode that must be given before any SIM change. This makes it harder for someone to transfer your number by impersonating you.
What should I do first if I suspect a swap?
Use another phone to call your carrier and confirm whether your number was moved, then secure your email and banking accounts. Acting fast limits how much access the fraudster gains.

Last reviewed: June 2026

Disclaimer: This page provides educational information only to help you recognise common scam patterns. It is not legal, financial, cybersecurity, or law enforcement advice, and it does not confirm whether any specific message, company, or person is genuine or fraudulent. When in doubt, contact the official organisation directly and report concerns to your local authorities.