---
schema_version: "1"
id: 949fd004fc5970e2e606d4b8512a03c5a441380c57e8a0d1f88849d9750d0231
title: User Profile Merge Logic
collection: admin
version: current
locale: en-us
portal_url: https://docs.salesforce.com/admin/current/en-us/mktg/264-0-0/mc_pers_identity_user_profile_merging_logic.md
canonical_url: https://help.salesforce.com/s/articleView?id=mktg.mc_pers_identity_user_profile_merging_logic.htm&release=264.0.0&type=5
source_site: help.salesforce.com
content_type: documentation
content_hash: 92ae8c20eaa4e9821a0eb68563f8d6f3892b74323005deb8b6adc720df5e98da
description: How Personalization merges two or more user profiles depends on whether or not those profiles share identity types.
products:
  - Marketing
  - Salesforce Personalization
release: "264"
---
# User Profile Merge Logic

How Personalization merges two or more user profiles depends on whether or not those profiles share identity types.

<table class="slds-table slds-table_bordered slds-max-medium-table_stacked slds-m-bottom_small ">
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          <th scope="col" class="slds-cell-wrap" style="vertical-align:top;" id="d73314e36">When Merging Occurs</th>
          <th scope="col" class="slds-cell-wrap" style="vertical-align:top;" id="d73314e39">When Merging Doesn’t Occur</th>
        </tr>
      </thead>
      <tbody>
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          <td data-label="When Merging Occurs" class="slds-cell-wrap" style="vertical-align:top;" headers="d73314e36 ">
            <p>​​When Personalization merges two or more user profiles, it stores all
              historic events, transactions, and interactions for those user profiles
              based on the following logic:</p>
            <ul>
              <li>
                <p>If an identity type exists for only one user profile, Personalization
                  retains that identity type and adds it to the merged user profile.</p>
              </li>

              <li>
                <p>If an identity type exists in more than one user profile,
                  Personalization retains the identity type with the latest timestamp
                  and adds it to the merged user profile. </p>
              </li>

              <li>
                <p>If metadata doesn’t exist or doesn't have a timestamp, Personalization
                  uses the system updated timestamp instead.</p>
              </li>

            </ul>
          </td>

          <td data-label="When Merging Doesn’t Occur" class="slds-cell-wrap" style="vertical-align:top;" headers="d73314e39 ">
            <p>If there isn't shared identity type data between the user profiles,
              Personalization doesn’t forcefully merge them. For example, Personalization
              doesn’t perform a request to rename, or merge, LoyaltyID 123 to LoyaltyID
              567 if there's no shared identity type data between the two user
              profiles.</p>
            <p>Even when there’s a matching identity attribute,
              Personalization doesn’t merge profiles under these conditions.</p>
            <ul>
              <li>When attempting to merge an anonymous user to a known user profile, but
                that known user profile currently has an active session.</li>

              <li>When attempting to merge anonymous user B with known user X, but
                anonymous user A already merged with known user X in the last 30
                minutes.</li>

            </ul>
          </td>

        </tr>
      </tbody>
    </table>