by SIM swap fraud is on the rise in the UK, with criminals targeting mobile numbers to gain access to bank accounts, emails, and other sensitive services. By the time victims notice their phone has no service, attackers may already be performing resets on multiple accounts. Awareness and preventive measures are critical to staying safe.
What Is SIM Swap Fraud?
SIM swapping is a type of identity theft where criminals transfer a victim’s mobile number to a SIM card they control. This allows them to receive two-factor authentication (2FA) codes and reset passwords for banking, email, and messaging accounts.
Key protective steps include:
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Never sharing your mobile PIN with your carrier
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Using biometric authentication on apps
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Limiting personal information shared online
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Monitoring bank accounts and credit reports regularly
Why Do Criminals Target Mobile Numbers?
SMS-based authentication is widely used, making mobile numbers a master key for online accounts. According to Experian UK and Ireland, attackers often have partial access to a user account and rely on phone verification to take full control.
The process is often highly coordinated, sometimes using automation or AI, with criminals mapping numbers to valuable accounts and exploiting mobile operators’ processes.
The Rising Trend in the UK
SIM swap attacks have skyrocketed in the UK, with Cifas reporting a 1,055% increase in unauthorized SIM swaps in 2024, totaling nearly 3,000 cases in the National Fraud Database. Identity fraud in the telecom sector rose 87%, and facility takeovers increased 76%, with 48% linked to mobile accounts.
AI-driven fraud is also increasing, with Experian noting a rise from 23% to 35% among UK businesses. Tactics include document forgery, brand-mimicking phishing, synthetic identities, and machine-generated text, indicating that attackers are improving both in volume and sophistication.
Older adults, particularly those over 61, are disproportionately affected, accounting for 29% of takeover incidents.
eSIM and Faster Takeovers
eSIM technology has streamlined SIM provisioning, making it faster to hijack accounts if attackers trick carriers. Attackers can remotely activate eSIMs through operators’ SM-DP+ systems, often using QR codes. Rapid processing of legitimate customer requests can inadvertently assist these attacks, emphasizing the importance of swift escalation in case of service loss.
Why SMS Codes Are Vulnerable
SMS-based 2FA is increasingly insecure. The UK National Cyber Security Center (NCSC) advises using app-based prompts or hardware security keys for authentication. Tools like passkeys and authenticator apps significantly reduce the risk of SIM-based account takeovers by linking logins to a cryptographic secret on a trusted device.
Banks are adopting these methods for high-value transactions, highlighting the importance of multi-layered authentication strategies.
How Telcos and Banks Are Responding
Telecom companies and financial institutions are strengthening defenses:
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Improved fraud detection models
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Enhanced document verification and selfie liveness checks
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Real-time detection of SIM changes, device reputation, and behavioral anomalies
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Cross-industry data sharing to identify fraud patterns
Ofcom is also tightening caller ID rules, extending blocks to international calls mimicking UK numbers, and consulting on measures to prevent spoofed calls targeting mobile users.
Signs of a SIM Swap and Immediate Actions
Common indicators of SIM swap fraud include:
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Sudden loss of mobile network service
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Emails notifying of SIM activation or password resets
Immediate steps:
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Contact your mobile provider from a different phone
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Alert banks and financial institutions
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Document every event and communication
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Switch high-value accounts to app-based or passkey authentication
Swift action can minimize the attacker’s window of opportunity and prevent further account compromise.
The Ongoing Cybersecurity Battle
SIM swap fraud represents a growing arms race between attackers and defenders. Hackers exploit weaknesses in onboarding and customer service, while providers improve adaptive checks to detect anomalies in real-time.
Key takeaway: Phone numbers remain vulnerable. Until cryptographic-based authentication becomes the standard, vigilance, multi-layered security, and prompt response are essential.
Bottom Line
SIM swap fraud is increasing due to reliance on SMS codes and the perceived security of mobile numbers. Consumers must adopt secure authentication methods, monitor accounts closely, and act immediately on any sign of service disruption. Banks and telcos should educate users about evolving threats, ensuring individuals can avoid becoming victims.
