Concern within UK organisations is shifting from “synthetics aren’t a problem” to “they might be, we just don’t know how to solve them”. According to recent TransUnion data, 91% of fraud leaders are now concerned about synthetic identities affecting their portfolios , with UK Finance estimating a £300m annual cost to UK financial institutions. Translating concern to impact, synthetics as a predominant cause of UK fraud losses grew from 13% in 2024 to 23% in 2025 – the same level as scams / authorised fraud.

Synthetic identities are built to deceive. In the US, they often centre around a stolen Social Security Number (SSN), alongside real and fictitious data. In the UK, the absence of a SSN arguably makes it easier: any name and date of birth tied to a genuine UK address can pass as legitimate, often evading traditional verification controls.

A typical synthetic identity journey may follow:

1. A fraudster creates a persona using fake personal details and a real UK address
2. They apply for low-value products, such as BNPL, mobile contracts and insurance to build a footprint
3. As the identity gains credibility, they access higher-cost, low-limit lending
4. They repay diligently, building a strong credit score
5. Eventually, they secure high-limit products, then bust out and vanish.

What makes synthetic fraud such a threat is its ability to go unnoticed for months, or years. Despite firms having fraud prevention and monitoring services, synthetic fraud is commonly misclassified as first-party fraud, No Intent to Pay, or credit defaults.

TransUnion works with organisations to rethink digital identity and to consider this as journeys, not static datapoints, through:

• activity analysis: Track behaviour across credit lines and longer time periods
• trust & risk signals: Link identities to email and mobile networks
• device intelligence: Detect evasion tactics and build device reputation views
• biometric verification: Use robust identity and selfie checks, with deepfake protection
• exposure screening: Periodically assess customer base for ‘sleeper synthetics’

Synthetic identities are a growing threat, especially as AI helps fraudsters bypass traditional checks. Building a clear picture of identity isn’t just about stopping fraud; it’s about protecting reputation, financial performance, and customer trust in a digital world – where appearances can deceive.