Troubleshooting and FAQs

Learn how to test, debug, and optimize your integration using Sigma Synthetic Fraud in RiskOS™.

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Note:

Most troubleshooting for Sigma Synthetic is covered in the Troubleshooting section of Sigma Identity Fraud.

Known issues

High Synthetic scores for consumers younger than 18

Preventing synthetic fraud requires validating that consumers really exist.
Younger demographics (under 18) often have thinner files and lower coverage, which results in fewer positive signals that an identity is real.
This is an area of active improvement in each new model release.

Use of last 4 digits of national ID for synthetic detection

Synthetic models are not fully optimized when only the last 4 digits of a national ID are provided.
In these cases, the national ID is usually treated as not provided.
New features and modeling techniques are in development to increase accuracy and add intelligence for partial national ID inputs.



FAQs

Synthetic Fraud

Why should I stop synthetic identities?

Synthetic identities in your portfolio can cause financial, operational, regulatory, and reputational harm.

  • Financial loss prevention: Fraudsters often build synthetic identities over time, establishing credit and multiple accounts before “busting out.” Blocking them early prevents large downstream losses.
  • Operational efficiency: Preventing synthetic identities reduces costly manual reviews and investigation overhead.
  • Regulatory compliance: Regulators expect effective fraud controls. Weak defenses against synthetics increase compliance risk.
  • Enhanced trust: Allowing synthetic identities erodes brand trust with consumers, partners, and investors. Strong prevention measures improve confidence across stakeholders.

Product questions

How is the model’s accuracy affected if certain PII values are missing?

The impact varies by model version and your population. Benchmark metrics are available in the Model Governance documentation via your Account Manager.

  • Synthetic identities are typically fabricated from manipulated names, national IDs, and DOBs. Missing these fields has the largest impact.
  • If a nine-digit national ID is unavailable, you can be configured with an alternative model flavor optimized for that scenario.
  • Missing other PII (e.g., phone, email, address) also reduces accuracy but to a smaller degree.

👉 Missing PII generally increases scores, raising false positives.

How can synthetic identities be detected when no national ID is provided?

Synthetic identities often rely on fake or mismatched Core PII (name, DOB, national ID).

Without a national ID, detection relies on whether the name + DOB combination is realistic.

  • Contact channels (address, phone) help constrain the search space and reveal links to other synthetic identities.
  • Manipulated DOBs (e.g., minors “upaging”) can be flagged even without national ID.

These checks increase detection confidence when national IDs are absent.


Actioning on Sigma Synthetic outcomes

Why should manipulated synthetic identities be stepped up to eCBSV?

Manipulated synthetics often alter only the SSN, while other PII remains valid.

This allows them to bypass document verification. Stepping them up to eCBSV ensures the SSN is validated against SSA records.

Why should fabricated synthetic identities be stepped up to Document Verification?

Fabricated identities should not have a legitimate ID document.

  • Document Verification prompts fraudsters to abandon the process (drop-off).
  • If attempted, fabricated IDs are flagged by Socure Predictive DocV.
Why might certain reason codes appear even when the overall score is lower?

Some risk signals are evaluated independently and may surface specific concerns even when the overall risk score is lower. This helps ensure that clear indicators of synthetic behavior are not overlooked.

Why might certain reason codes not appear even when the overall score is high?

Not all high-risk cases surface the same supporting signals. In some cases, overall risk may be elevated without triggering specific reason codes.

Customers should define escalation strategies based on their overall risk tolerance and downstream verification approach.