Duplicate detection

One person opening several accounts, to claim a bonus twice or to come back after a ban, shows up as the same face under different external_ids. Duplicate detection compares each new selfie with the faces already verified in the workspace and tells you when it finds a match.

When it runs

Duplicate detection runs when the workspace’s Allow duplicate accounts setting is off:

Workspace type	Duplicate detection
Identity (KYC)	Yes, when duplicate accounts are not allowed
Age verification by ID document	Yes, when duplicate accounts are not allowed
Facial age estimation	Yes, when duplicate accounts are not allowed

Allow duplicate accounts is on by default, which turns the check off. Turn it off in the workspace settings if one person should have one account. It compares faces within the workspace and against verifications of other people: a face returning under the same external_id is the same account verifying again, not a duplicate. Test workspaces do not run it.

It reports, you decide

Finding a duplicate does not decline the verification: the verification is decided on its own checks, and the duplicate is reported next to the decision. What to do with it depends on your business, so the decision is yours: refuse the new account, link it to the old one, or send it to your own review.

In the API and the webhook

The verification’s duplicate_check:

{
  "checked": true,
  "duplicate_count": 1,
  "duplicates": [
    {
      "verification_id": "771a9200-c3df-4e88-b201-112233445566",
      "external_id": "user_987",
      "similarity_score": 0.91,
      "verified_at": "2026-08-14T09:12:44+00:00"
    }
  ]
}

checked is false when the check did not run. The webhook carries a shorter form, present only when a duplicate was found:

{
  "duplicate_detected": true,
  "duplicate_count": 1,
  "duplicate_of": { "verification_id": "771a9200-c3df-4e88-b201-112233445566", "external_id": "user_987" }
}

Reasons

None: a duplicate never sets reason.

Selfie checks

Document checks

Fraud prevention

Reference

Duplicate detection

When it runs

It reports, you decide

In the API and the webhook

Reasons

​When it runs

​It reports, you decide

​In the API and the webhook

​Reasons

When it runs

It reports, you decide

In the API and the webhook

Reasons