SIM Swap Attacks: How They Work and How to Prevent Them

A SIM swap attack is when a fraudster convinces your mobile operator to transfer your phone number to a SIM card they control. Once they have your number, they have the keys to your digital life.

What Can They Do With Your Number?

• Access your mobile money (MoMo) accounts
• Reset passwords on your email and social media
• Intercept SMS verification codes
• Impersonate you to your contacts
• Empty your bank account

How SIM Swaps Happen

The attacker typically:

1. Gathers your personal information — from social media, data breaches, or social engineering
2. Contacts your mobile operator — by phone, in a shop, or online
3. Impersonates you — using your name, date of birth, ID number
4. Requests a SIM replacement — claiming their SIM was lost or damaged
5. Receives your number on their SIM — and you lose signal

Warning Signs

• Your phone suddenly loses signal (no bars, "No Service")
• You cannot make calls or send texts
• You receive notifications about account changes you did not make
• Friends say they received messages from you that you did not send

How to Protect Yourself

1. Set a SIM PIN

Contact your mobile operator and set a SIM PIN that must be provided for any SIM changes. This is the single most effective protection.

2. Protect Your Personal Information

• Do not share your ID number, date of birth, or mother's maiden name publicly
• Be cautious about what you post on social media
• Never give personal details to callers claiming to be from your operator

3. Use App-Based 2FA

Wherever possible, use Google Authenticator or Authy instead of SMS for two-factor authentication. App-based 2FA cannot be intercepted by SIM swap.

4. Register for Alerts

Most mobile operators offer transaction alerts. Enable SMS and push notifications for all account changes.

5. Act Fast If It Happens

If you suddenly lose signal:

1. Try to call your own number from another phone
2. Contact your mobile operator immediately from a different line
3. Lock your mobile money accounts
4. Change passwords on email and social media from a secure device

Report It

In Ghana, report SIM swap fraud to your mobile operator's fraud department and the Economic and Organised Crime Office (EOCO).

Take the full course: Mobile Money Fraud and Financial Safety