---
title: "How OnceHub Handles Duplicate Contacts"
description: "Learn how OnceHub detects and merges duplicate contact records to maintain a single, accurate record for each guest."
url: "https://help.oncehub.com/contact-management/how-oncehub-handles-duplicate-contacts"
---

If you update a guest’s email address or mobile phone number to one that is already associated with another contact record, OnceHub displays the **Merge Contacts** prompt. This allows you to merge duplicate contacts into a single record, helping maintain one complete record for each guest.

For an overview of how contacts are managed in OnceHub, see [**Managing Contacts in OnceHub**](https://help.oncehub.com/contact-management/managing-contacts-in-oncehub/) article.

***

## How Contacts are Identified

[Section titled “How Contacts are Identified”](#how-contacts-are-identified)

To prevent duplicate records, OnceHub automatically runs a matching process whenever an activity, import, or manual update occurs. OnceHub checks for matching record using the following sequence:

1. **Email address (Primary identifier):** OnceHub searches for a matching email address across existing records.
2. **Mobile phone number (Secondary identifier):** If no matching email address is found, OnceHub checks for a matching mobile phone number.

If a match is found, OnceHub flags the record as a duplicate, initiates the merge process, and updates the existing record with the incoming information.

For more details, see [**How Contacts Are Identified In OnceHub**](https://help.oncehub.com/contact-management/how-contacts-are-identified-in-oncehub/) article.

***

## Understanding the Merge Process

[Section titled “Understanding the Merge Process”](#understanding-the-merge-process)

When the **Merge Contacts** prompt appears, OnceHub combines information from both contact records using the following rules:

* **Add missing values:** If the new contact record contains a value for a field that is blank in the existing record, that value is added.
* **Update existing values:** If both contact records contain a value for the same field, the new value replaces the existing value after you confirm the merge.
* **Keep existing values:** Blank fields in the new contact record never overwrite existing values.

Note

Always review the merge details carefully in the Merge contacts prompt before confirming the action.

**Permission requirements:** You can only merge contact records only if you have permission to access both records. For more information, see [**User Roles and Their Permissions**](https://help.oncehub.com/account-administration/user-management/user-roles-and-their-permissions/) article.