OneMerge How to Create Cross Object Merge

Duplicate Rules, a standard Salesforce feature, support cross-object matching e.g. Lead to Contact and can alert, block or report the creation of duplicates. OneMerge takes this process one step further by enabling Leads to be flagged as duplicates automatically at the time of creation (or edit) and to show the matched Contacts in a related list on a Lead page layout. The following steps provide an example use case.

Step 1 

To create a Cross Object Merge, follow these steps to setup the configuration:

1. Navigate to the Duplicate Rules provided as standard in setup (see below).
2. Select the Standard Rule for Leads with Duplicate Contacts and Activate.
3. Navigate to Custom Metadata Types.
4. Clone the Standard Merge Ruleset for Leads (just do the original is not reconfigured).
5. Ensure the following configuration requirements are set:
   1. Cross Object Merge Action = “Custom Merge”.
   2. Last Merged Date Field Name = Last_Duplicate_Check_Date__c.
   3. Is Merge Master Checkbox Field Name = Is_Duplicate_Lead__c.
   4. “Lead_to_Contact” Merge Object Mapping.
6. Navigate to Merge Object Mapping and create a new Object Mapping as per the second screenshot below.
7. Ensure the following configuration requirements are set:
   1. Last Merged Date Field Name = Last_Matched_Lead_Date__c. Custom Field: Type=DateTime, Label=Last Matched Lead Date.
   2. Master Record Field Name = Last_Matched_Lead__c. Custom Field: Type=Lookup, Object=Lead, Label=Last Matched Lead.
8. Navigate to the Guided Setup and select the Application Settings.
9. Ensure the ‘Is Triggers Active?’ and ‘Is Realtime Merge Active’ are set to True.

Step 2

To test the configuration setup for Cross Object Merge, follow these steps:

1. Create a new Contact.
2. Create a new Lead with the same credentials as the Contact.
3. The Contact fields Last Matched Lead and Last Matched Lead Date are updated within the Contact Record.
4. The Lead fields Is Duplicate Lead? and Last Duplicate Check Date are updated within the Lead Record.
5. The Lead related list Matched Contacts shows the test Contact.

Additional Information

The following Blog Post provides further screenshots and more detailed information https://onemerge.co.uk/blog/deduplicate-salesforce-leads-against-contacts/. There are some custom configuration requirements, as per the information provided in the post.

The demo below also provides an example using Contacts and Leads.

If you require any assistance with Cross Object Merge or indeed anything else regarding OneMerge Free Edition, Standard Edition or Enterprise Edition, please do not hesitate to contact us at hello@onemerge.co.uk.

Article last reviewed: 2026-02-17