SIM Swap Attacks Fall 99% at T-Mobile

T-Mobile credits tighter identity checks and hardware keys, a company-reported result that independent testing has not yet confirmed.

Updated on Nov. 2, 2026 in Cybersecurity

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Do you trust your phone carrier to protect your number from SIM swap attacks?

T-Mobile reported in a cybersecurity report that successful SIM swap attacks against its customers have fallen more than 99% since 2022. The company credits tighter identity checks, biometric verification, and new account protections, and this is a company-reported result, not an independent audit.

Why it matters

SIM swap fraud lets attackers take over a phone number and intercept the one-time codes used to reset account passwords, so reducing it targets a common route to account takeover. The report also shows a carrier pairing self-service restrictions with hardware-based authentication, a pattern other telecoms and account providers may weigh as they manage the tradeoff between convenience and security.

T-Mobile's company-reported figures show a more than 99% decline in successful SIM swap attacks since 2022 and a 37% rise in attempted intrusions over a recent 12-month period. The report does not explain how it measured successful attacks, and the rise in attempts could reflect either more activity or improved detection.

The players

T-Mobile

A major U.S. wireless carrier that publishes its own security metrics on SIM swap fraud, phishing, and spam blocking across its network and workforce.

Salt Typhoon

A state-linked hacking group that T-Mobile says attempted to access sensitive customer communications during a 2024 intrusion, which its defenses stopped.

The details

A SIM swap attack tricks a carrier into moving a victim's phone number to a SIM card controlled by the attacker, so the attacker receives calls and texts meant for the victim. T-Mobile says it reduced these attacks by adding stronger identity checks and biometric verification, along with SIM Protection and Port-Out Protection, which guard against unauthorized changes to a line. On the employee side, the company moved staff logins to FIDO2 hardware security keys, physical devices that cryptographically confirm a login without sending a reusable password that phishing could capture.

2017: T-Mobile begins counting unwanted calls it has identified or blocked, which now exceeds 160 billion.
2022: T-Mobile restricts self-service SIM transfers amid security concerns, the baseline for the 99% decline.
2024: T-Mobile says its defenses stopped the Salt Typhoon hacking group during an intrusion attempt.
2025: T-Mobile restores self-service SIM transfers through its T-Life app and blocks nearly three billion scam and spam texts.
2026-11-02
T-Mobile publishes its cybersecurity report.

The Tech Race

T-Mobile's approach of restricting self-service SIM changes and then restoring them after authentication improved shows how carriers are trying to balance account convenience against fraud. The company's passwordless FIDO2 rollout for employees places it among firms moving from one-time codes and passwords toward hardware-backed login.

Customers who have had their phone numbers or accounts taken over by SIM swapping may see fewer such attempts, though T-Mobile has not announced a timeline for further changes beyond the restored T-Life self-service transfers. Users should check whether their carrier offers SIM protection or port-out locks, since these features are what the company credits for the reduction.

The takeaway

Watch whether T-Mobile's next report confirms the 99% decline with independent measurement or shows the same pattern as attempted intrusions keep rising. Also watch whether other U.S. carriers adopt similar biometric checks and hardware-key authentication in response.