A London man received a two-and-a-half-year prison sentence on Thursday for his role in a SIM-swap fraud that stole almost £200,000 ($265,000) worth of cryptocurrency, City of London Police said.

Ajay Shinjin, 25, also known as AJ Marley Cruz, was sentenced at Inner London Crown Court after pleading guilty on September 28 to conspiracy to commit fraud by false representation and transferring criminal property. Police described the scheme as "complex and calculated."

Shinjin, of Marsh Wall, Canary Wharf, received more than £44,000 of the stolen funds. He spent the money on luxury holidays in Dubai, a high-end Canary Wharf apartment and gold-plated teeth grills, according to the force.

How did the fraud work?

In a SIM swap, criminals take control of a victim's phone number by having it transferred to a SIM card they control. They can then intercept the one-time passcodes that banks and crypto platforms send by text message, bypassing account security entirely.

BT detected the scheme in early November 2021, identifying unauthorized activity on its systems through which customer phone numbers had been moved to criminals' SIM cards. The telecoms operator traced the devices used to receive the transferred numbers, and its data led police to several suspects — including Shinjin, who was linked to four of the devices.

The losses were spread across at least four victims:

• One victim lost about £40,000 in crypto on November 2, 2021, of which roughly £27,000 went into Shinjin's personal crypto account.
• A second victim's entire loss of approximately £17,000 ended up in his wallet.
• He helped steal about £8,000 from a third victim's Coinbase account.
• A fourth victim lost approximately £130,000.

What was the investigation trail?

Police first arrested Shinjin at his flat in 2021. Officers re-arrested him at Heathrow Airport in October 2023 as he returned from Dubai, after further evidence came to light. He gave no comment in police interviews.

"SIM-swap fraud is a sophisticated and increasingly concerning form of offending, and this case demonstrates the devastating consequences it can have for victims," said Detective Constable Simon Ardeman of the City of London Police.

The conviction underscores the operational exposure created when SMS-based one-time passcodes remain the primary control protecting exchange and banking accounts. Once a phone number is ported, an attacker inherits the authentication layer itself.

Is SIM swapping getting worse?

The numbers point one way. Unauthorized SIM swap cases recorded to the UK's National Fraud Database rose 402% in the first half of 2026 compared with the same period a year earlier, fraud prevention service Cifas reported in August. Cifas attributed the surge to SIM swaps increasingly being used to intercept security codes and defeat account protections.

Mark Birchall, staff cybersecurity editor at Norton, recommends switching two-factor authentication from text messages to an authentication app, which ties account access to a physical device rather than a phone number. He also advises setting a separate PIN or passcode with the mobile carrier where possible, and enabling account takeover protection — a feature some carriers offer that imposes strict verification rules on any account changes.

A phone number "may not be the best way to verify your identity," Birchall wrote.

For crypto platforms, the case adds pressure to move customers away from SMS-based verification. With UK SIM-swap reports up more than fivefold year on year and carriers and law enforcement now actively tracing device-level evidence, exchanges that still rely on text-message passcodes face a narrowing window to harden their account-recovery flows.