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The blocklist feature automatically declines verification sessions that match previously identified documents, faces, phone numbers, or emails that should be rejected. This helps prevent fraud and ensures the integrity of your verification process.
Blocklist dialog in the Didit console

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Overview

The blocklist operates on four entity types:

Document blocklist

Prevents reuse of specific documents identified as fraudulent, stolen, or otherwise problematic.

Face blocklist

Prevents users whose biometric data matches previously blocklisted faces from passing verification.

Phone number blocklist

Prevents verifications using phone numbers that have been blocklisted.

Email blocklist

Prevents verifications using email addresses that have been blocklisted.
When a blocklisted entity is detected during verification, the session is automatically declined with the corresponding warning: ID_DOCUMENT_IN_BLOCKLIST, FACE_IN_BLOCKLIST, PHONE_NUMBER_IN_BLOCKLIST, or EMAIL_IN_BLOCKLIST.

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How blocklisting works

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Document blocklisting

When a document is added to the blocklist, the system stores secure fingerprints of the document’s unique identifiers (document number, MRZ data, etc.). During future verification sessions, if a document matches these fingerprints, the session is automatically declined. Useful for:
  • Preventing reuse of known fraudulent documents
  • Blocking documents reported as stolen
  • Preventing multiple accounts using the same document

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Face blocklisting

When a face is added to the blocklist, the system stores biometric templates derived from facial features. These templates are compared against faces in new verification sessions. Useful for:
  • Preventing users who have attempted fraud from creating new accounts
  • Enforcing platform bans across new registration attempts
  • Implementing regulatory exclusion requirements

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Phone number blocklisting

When a phone number is added to the blocklist, the system evaluates new verification sessions against the blocklisted numbers (including normalized E.164 formats). Useful for:
  • Blocking numbers associated with repeat abuse or policy violations
  • Preventing re-registration attempts using the same phone number
  • Enforcing regional compliance requirements

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Email blocklisting

When an email address is added to the blocklist, the system checks new verification sessions against blocklisted addresses (case-insensitive, normalized). Useful for:
  • Preventing repeat fraud or spam attempts from the same email address
  • Enforcing bans across multiple accounts tied to the same email
  • Meeting compliance requirements for account creation

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Managing the blocklist

Items can be added to the blocklist through:
  • The Didit Console — navigate to the blocklist section and add items manually.
  • The Blocklist API — programmatically manage blocklist items. See the Blocklist API reference.
For API-based blocklist management, see the Add to blocklist, Remove from blocklist, and List blocklist items endpoints.