In brief

  • A London man has been jailed for two and a half years over a SIM-swap fraud that stole almost £200,000 worth of cryptocurrency, City of London Police said.
  • Ajay Shinjin received more than £44,000 of the stolen funds and spent it on Dubai holidays, a high-end apartment and gold-plated teeth grills.
  • BT found in November 2021 that customer phone numbers had been moved to SIM cards controlled by criminals, who used them to intercept one-time passcodes.

A London man has been jailed for two and a half years for his role in a “complex and calculated” SIM-swap fraud that stole almost £200,000 ($265,000) worth of cryptocurrency, City of London Police said Thursday.

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.

He received more than £44,000 of the stolen funds, which he spent on luxury holidays in Dubai, a high-end apartment in Canary Wharf and gold-plated teeth grills.

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 receive the one-time passcodes that banks and crypto platforms send by text.

In early November 2021, BT identified unauthorized activity on its systems through which customer phone numbers had been transferred to criminals' SIM cards. BT traced the devices used to receive the numbers, and its data led police to several suspects, including Shinjin, who was linked to four of the devices.

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

Shinjin was first arrested at his flat in 2021, and re-arrested at Heathrow Airport in October 2023 on his return 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.

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Preventing SIM swaps

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 last year, fraud prevention service Cifas reported in August. Cifas said the rise reflects SIM swaps increasingly being used to intercept security codes and bypass account protections.

Mark Birchall, staff cybersecurity editor at Norton, recommends using an authentication app for two-factor authentication rather than text messages, which ties account access to a physical device rather than a phone number.

He also advises setting a separate PIN or passcode with your mobile carrier where possible, and enabling account takeover protection, which some carriers offer to set strict verification rules for any changes to an account.

SIM swapping is one reason a phone number "may not be the best way to verify your identity," Birchall wrote.