> ## Documentation Index
> Fetch the complete documentation index at: https://documentation.idenfy.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Duplicate Check

> Detect and manage duplicate identity verifications using biometric face matching and document comparison tools in the iDenfy dashboard.

* [ What Does the Duplicate Feature Do?](#Duplicatecheck-WhatDoestheDuplicateFeatureDo?)
* [ Why It Matters](#Duplicatecheck-WhyItMatters)
* [How It Works](#Duplicatecheck-HowItWorks)
* [Possible outcomes](#Duplicatecheck-Possibleoutcomes)

## What Does the Duplicate Feature Do?

The **Duplicate Check** helps prevent fraud by detecting if the **same person tries to register multiple times**.

It compares a new customer’s **face** against your existing database of completed verifications.

***

## Why It Matters

The feature instantly helps you:

* **Stop Bonus Abuse** – blocks the same person from repeatedly claiming “new user” promotions.
* **Identify Fraud Rings** – detects individuals using many different stolen or fake IDs.
* **Block Banned Users** – prevents fraudsters who were rejected from re-registering.

***

## How It Works

* **Separate checks** – Face and Document Face are checked independently. You can run duplicates on the **selfie**, **document photo**, or **both**.
* **Automatic check** – Every time you perform a verification, the system runs a duplicate check.

<Info>
  **Good to know**

  * If you use the same **clientId** for the same user, the **Duplicate** feature will not add a tag - we assume you’re making a **re-verification**
</Info>

### Possible Outcomes

1. **No match found** → Verification is approved as usual.
2. **Match found** → The user is marked as **Approved (Suspected)**.

* The verification is still **valid** since all submitted data is correct.
* You decide whether to **onboard** or **deny** the customer.

3. **Verification denied for other reasons** → Duplicate check is **not performed**.