How Hybrid (Synthetic) Merges Work in Koalify

By default, HubSpot’s native merge process creates a new primary record when companies are merged. While this behavior works well for many use cases, it can introduce challenges in environments where integrations depend on existing HubSpot record IDs or where merge history limits may be reached.

Koalify provides an alternative merge method called a Hybrid Merge (also referred to as a Synthetic Merge). This approach closely replicates HubSpot’s native merge outcome while avoiding several platform limitations.

During a Hybrid Merge:

• The secondary company is deleted

• The existing primary company is updated with combined data

• No new company record is created

Important information such as property values, activities, and associations is preserved and consolidated on the primary company record.

Why use a Hybrid/ Synthetic Merge in HubSpot?

1) Salesforce integration

Historically, HubSpot did not support company merges when the Salesforce integration was active, including through the API.

Hybrid merges provide an alternative approach that allows records to be consolidated without relying on HubSpot’s native merge process.

2) Preserve HubSpot Record IDs

HubSpot’s native merge creates a new record, which results in a new HubSpot record ID. This can break external integrations or internal processes that rely on stable record IDs.

Some integrations or systems rely on stable object identifiers. Because a Hybrid Merge updates the existing primary record instead of creating a new one, it helps prevent downstream integration issues.

3. Avoid HubSpot’s merge ID storage limit

HubSpot stores merged record IDs on the primary record but limits this to 250 stored merge IDs. In environments with high deduplication volume, this limit can be reached.

A Hybrid Merge avoids this limitation because no new merged record is created.

How Koalify’s Hybrid Merge works

Koalify sythetic merges are designed to behave like HubSpot’s native merges, with a few important differences:

General behavior

• No new company record is created
• The secondary company is deleted
• The primary company is updated with selected data from the secondary record

Standard properties

• If the primary record already has a value → it remains unchanged
• If the primary record is empty and the secondary has a value → the secondary value is used

you can also customize property behavior with Koalify merge rules

Read-only properties

Properties that cannot be written via the API are not updated, including:

• Analytics properties

• Calculated fields

• System-generated properties

Activities (calls, emails, tasks, meetings)

• All activities from both records are combined under the primary company

Associations (contacts, deals, tickets, etc.)

• Associations are merged unless this would exceed HubSpot’s association limits

• If the limit is exceeded, the merge won’t complete, you’ll need to reduce associations first

Associated leads

• Due to HubSpot API limitations, only leads linked to the primary company are retained

• Leads associated with the secondary company will not be preserved

Workflows

• The primary company may be enrolled if updated data matches workflow criteria

• The secondary company is automatically unenrolled when it is deleted