Updated on the 5th of August 2025
This post describes common issues with merging Salesforce Accounts and Contacts where the Account Setting Allow users to relate contacts to multiple accounts is enabled. The screenshot below shows the setting and the related options. Additional information is provided in the Salesforce Help.
Account Settings – Contacts to Multiple Accounts
When Contacts to Multiple Accounts is enabled a new standard object AccountContactRelation becomes visible which stores the various relationships between accounts and contacts; either the direct and implicit Contact parent Account or indirect and explicitly added relationships with optionally one or more role. The relationships are managed via the Related Accounts and Related Contacts related lists which can be added to the Contact and Account page layouts respectively. The screenshot below shows the Contact Related Accounts related list and the basic attributes of a relationship. Additional information is provided in the Salesforce Help.
Contact Related Accounts
The functionality described above provides a flexible model for representing Account and Contact relationships.
When Account and Contact records are merged the following considerations apply to the handling of relationships.
Contact Merge
- Indirect Account relationships are reparented.
- Direct Account relationships are lost: indirect Account relationships are not added to the winning Contact for the losing Contact direct Account relationships
- If multiple relationships (direct or indirect) exist to the same Account then the merge will fail with the error below. For example, a redundant relationship would exist if the winning Contact and a losing Contact both have indirect relationships to the same Account.
MERGE_FAILED, These contacts have the same related account. Open the related account record and remove redundant account–contact relationships. Then try merging again.
Account Merge
- Indirect Contact relationships are reparented.
- If multiple relationships (direct or indirect) exist to the same Contact then the merge will fail with the error below. For example, a redundant relationship would exist if the winning Account has an indirect relationship to a child Contact of a losing Account.
MERGE_FAILED, These accounts have the same related contact. Open the related contact record and remove redundant account–contact relationships. Then try merging again.
In summary, there are 2 issues to be mitigated; data loss where the parent Account relationship is lost (for losing records) when Contacts are merged (Contact point 2) and the technical error where duplicate relationships exist across the records being merged (Contact point 3 and Account point 2). In both cases a manual process is typically required either to recreate or deduplicate relationship records respectively.
OneMerge provides a complete solution to both noted issues which ensures that relationships are managed correctly across all automated or manual merge operations. For the 1st issue, OneMerge will add indirect Account relationships to the winning Contact for the losing Contact direct Account relationships and for the 2nd issue redundant relationships are avoided by deduplication of the relationship data within the merge operation.
August 5th 2025 Update. With the OneMerge Summer ’25 release additional functionality has been added to consolidate Role values across duplicate relationships to avoid data loss. Additionally, where Start and End Dates have been added to the relationships flagged as active, the deduplicated relationship record will have the earliest Start Date and the latest End Date values.
Thanks for reading.