HubSpot Merge Duplicates Module Overview

Insycle supports merging the following HubSpot object types:

• Companies
• Contacts
• Courses
• Deals
• Leads
• Line Items
• Listings
• Orders
• Tickets
• Custom Objects

You can select the object type you would like to work with in the top menu of the module.

The following describes how data is consolidated using the default merge method for each HubSpot object type:

Contacts

• Record ID: A unique Record ID is created for the new resulting merged record (contacts always use Native merge).
• Email address: The email address from the master record becomes the primary, and the duplicate email addresses are added as additional email addresses.
• Fields/Property values: 
  • To customize how field data is retained in the master record on a field-by-field basis, use the Field tab under Step 3.
  • By default, the value is retained from the master. When a value is empty in the master, it picks a non-empty value from the most recently updated duplicate. All other values are available in the history. 
  • Multi-select picklist fields: All selected values from duplicate records and the master are automatically consolidated into the master record. For example, if the master record has the value "Newsletter" and a duplicate has the value "Product Updates," the merged record will contain both "Newsletter" and "Product Updates."
  • Certain specific fields are uniquely handled by HubSpot. These will trigger special messages in the CSV that indicate how values are retained. See the table "Special CSV messages for select HubSpot contact fields" below for details.
• Associated deals, contacts, companies, and any other objects: Reassigned from the duplicates to the master.
• Activities (notes, emails, tasks, etc.): Reassigned from the duplicates to the master.
• Attachments: Reassigned from the duplicates to the master. (Note that there may be a short delay before the attachment appears in the merged record.)

Companies

• Record ID: The Record ID from the master record is kept when HubSpot-Salesforce sync is enabled (uses Synthetic merge by default). Otherwise, a unique Record ID is created (uses Native merge by default).
• Domains: Copied from the duplicates into the master and appended as secondary domains to avoid future duplicates with the same domain.
• Fields/Property values: 
  • To customize how field data is retained in the master record on a field-by-field basis, use the Fields tab under Step 3.
  • By default, the value is retained from the master. When a value is empty in the master, it picks a non-empty value from the most recently updated duplicate. All other values are available in the history.
  • Multi-select picklist fields: All selected values from duplicate records and the master are automatically consolidated into the master record. For example, if the master record has the value "Newsletter" and a duplicate has the value "Product Updates," the merged record will contain both "Newsletter" and "Product Updates."
• Parent company associations: If you don't configure this field in Step 3 on the Fields tab and the master record has no parent company, Insycle automatically keeps the parent company from the most recently modified duplicate record that has one. To override this behavior, configure the Parent Company field on the Fields tab of Step 3.
• Associated deals, contacts, companies, and any other objects: Reassigned from the duplicates to the master.
• Activities (notes, emails, tasks, etc.): Reassigned from the duplicates to the master.
• Attachments: Reassigned from the duplicates to the master. (Note that there may be a short delay before the attachment appears in the merged record.)

Courses, Deals, Leads, Line Items, Listings, Orders, Tickets, and Custom Objects

• Record ID: A unique Record ID is created for the new resulting merged record (uses Native merge by default). When using Synthetic merge, the Record ID from the master record is kept.
• All other properties, apart from Domain, follow the same merge logic as company records.

Learn more about HubSpot's merging behavior.

Special CSV messages for select HubSpot contact fields

When you include certain fields in Step 3, Master rules, a special message will appear in the Master (After) row of the CSV. These fields do not follow the standard merge logic, and the message lets you know how HubSpot will choose the value. This applies to the following fields:

See HubSpot's contact merge exceptions info to learn more.

Insycle Merge Process

When merging HubSpot records, Insycle goes through the following steps:

1. Select the master record according to the rules set in Step 3: Merge Logic, Master tab.
2. Determine field values to retain in the master record based on rules configured in Step 3: Merge Logic, Fields tab.
3. For fields without specific rules, identify non-empty values using a "fill in the blanks" method:
   • Check whether the master record has any empty fields.
   • If empty, copy values from the most recently updated record in the duplicate group.
4. Update the master record by:
   • Applying the field values chosen in #2 (from Field rules).
   • Adding the non-empty values identified in #3 (using "fill in the blanks").
   • Preserve all other existing values in the master record.
5. Merge the duplicate records and reassign all related objects to the master record.
6. Store an audit trail report accessible from the Activity Tracker and send an email notification to the designated recipients.

There are unique features and applications for HubSpot's Native merge functionality compared to the Synthetic merge capabilities provided by Insycle. While both methods may be available for most object types, the default method varies. This option is available on the Method tab under Step 3.

Native Merge vs. Synthetic Merge Comparison

When to use the Synthetic merge:

• Record ID: When you want to retain the master record and record ID instead of creating a new record.
• Salesforce integration: To merge companies when the HubSpot Salesforce integration is enabled.
• Parent-child relationships: If you have complicated parent-child associations that aren’t merging properly, Synthetic merge can automatically handle reassigning relationships.
• 250+ duplicates: HubSpot limits the number of duplicates that can be merged into a single record to 250. Synthetic merge lets you bypass this cap.
• Revert: If there's a chance you'll want to unmerge records later. Learn how to partially restore merged duplicates and undo the changes to the master records.

  Note that due to its complexity, the Synthetic merge may take longer to run than the Native merge. 

Though you can create custom data retention rules for any record fields using the Fields tab under Step 3, it is not required. There is no need to create rules for every field in your CRM - Insycle automatically handles fields without specific rules with a "fill in the blanks" approach. 

When the master record has empty fields, Insycle copies values from the most recently updated record in the duplicate group where that data exists. For example, if the master record's Industry field is empty but another record in the duplicate group has an Industry value, that value will automatically be copied to the master record. 

This means you only need to create custom retention rules for the fields that require special handling, rather than setting up rules for all your fields.

Step 1 is where you define which fields Insycle should examine to find duplicate records, and set the rules for how those fields are compared. Each field you add is cumulative — records must match all of the criteria you specify to be flagged as potential duplicates. For example, matching on First Name AND Last Name AND Email Domain returns only results where all three values are the same.

Step 1 operates through three tabs:

• The Simple tab is where you add matching fields and configure comparison rules, ignored elements, match parts, and conditions.
• The Advanced tab is where you configure Related Fields for any field already added on the Simple tab.
• The Conditions tab is where you set conditions for any field already added on the Simple tab.

A field must be added on the Simple tab before it can be configured on the Advanced or Conditions tabs.

See the Duplicate Identification Rules Reference for a complete breakdown of every option.

Additionally, Step 1 includes a CSV tab that lets you upload a file of known duplicate record ID pairs directly — bypassing field-based matching entirely. See the CSV Tab Reference for details.

Step 2 displays all duplicate groups identified in Step 1, allowing you to review and verify the matches before proceeding. Records that match your Step 1 criteria are automatically clustered into duplicate groups — each group represents a single entity and shows how many duplicate records it contains. For example, four records for the same person would appear as a single duplicate group containing four records.

Click the chevron  at the right end of a duplicate group row to expand it and examine the individual records within that group. You can also add more fields as columns to give yourself further context when evaluating the matches.

To exclude a duplicate group from all future deduplication analysis, click the X on the group row. Excluded groups will not appear as duplicates or be included in merges, even when using different duplicate detection templates. To review and manage excluded groups, click the Exclusions button in the Step 2 header.

Bulk vs. Manual

Step 3 is where you configure how duplicate groups are consolidated—from choosing your operation mode to defining master selection rules and field retention logic. This step combines operation selection with the merge logic configuration through multiple tabs.

At the top of Step 3, choose between Bulk and Manual modes in the header:

• Bulk mode (recommended) automatically merges all duplicate groups according to the master record selection rules you define in the Master tab. This is the right choice for most deduplication processes, and the only mode that supports templates, Recipes, and automation.
• Manual mode lets you review and select specific records to merge individually from the Record Viewer. Reserve this for high-value records or complex scenarios where you want hands-on control over each merge. Learn more about merging using Manual mode.

Step 3: Master Tab

The Master tab of Step 3 lets you set the rules that determine which record in each duplicate group becomes the master. Insycle evaluates your rules in order from top to bottom, and the first record that uniquely matches a rule becomes the master. If no record matches any rule, master selection fails for that group. See the Master Record Selection reference for a full breakdown of all rules and options.

At the bottom of the Master tab, you'll also configure:

• Processing method — Choose between By Priority (evaluates rules in sequence, stops at first unique match) or Absolute (master must match all rules). Most operations should use By Priority.
• Exclusions — By default, Insycle skips any duplicate group containing more than 5 records—this prevents overly broad matching criteria from accidentally merging unrelated records. You can adjust this threshold up to 100 records per group.

Step 3: Fields Tab

The Fields tab in Step 3 controls which field values are copied to the master record after the merge. By default, Insycle keeps the master record's values and fills any empty fields with values from the most recently updated duplicate. You can override this on a field-by-field basis for any fields that need special handling. See the Field Data Retention Reference for all available criteria and conditions.

Step 3: Method Tab

On the Method tab of Step 3, you choose between Native and Synthetic merge logic and control whether empty master fields are automatically filled. See the Method Tab Reference for details.

Preview vs. Update Mode

Step 4 is where you preview and apply your merge changes. It operates in two modes:

• Preview Mode generates a CSV report that shows exactly how your records would be merged based on your current configuration — which records become masters, which field values end up where, and whether any errors occur. No changes are made to your CRM. Always run Preview Mode before Update Mode to verify everything is working as expected.
• Update Mode applies the merge to your live CRM. Once you've confirmed your Preview results look correct, Update Mode executes the actual merge operations.

Confirmation Prompt

When the Merge API is set to Synthetic on the Module tab in Step 3, running in Update Mode displays a Please confirm dialog before the operation begins. This dialog shows an estimated time for the merge based on the number of associations and engagements that need to be reassigned. 

Click Yes to proceed. 

Processing time for Synthetic merges depends on the volume of associated records and will be longer than Native merges — avoid running multiple operations in parallel on the same database. You can monitor progress in the Activity Tracker.

CSV Report File

The CSV report includes records from all duplicate groups. It shows the current state of the master record, excluding reassignments of associated contacts, deals, or activities. (To verify how these reassignments happen, run a small test in Update mode.) This guarantees that the CSV accurately represents the merge setup before executing in Update mode.

The Duplicate Group ID indicates which records will be merged together. 

The Status column indicates:

• Duplicate – The record is part of a duplicate group.
• Master – The master record chosen for the duplicate group based on default behavior and your Master rules. Review the selections in this row to determine whether the appropriate records are being chosen.
• Master (After) – For each duplicate group, a special row –Master (After)– will appear in the CSV report. The Master (After) row shows the values the final record will contain based on your Field rules and the default behavior. For certain fields included in the Step 3 Master rules, a special message will appear in the Master (After) row. View the HubSpot Merge Logic Explained above for details.
• Error – If Insycle is not able to determine which record would be the master, an error message will appear here. See the Troubleshooting section below for more details.

After you've seen the results in HubSpot and you are satisfied with how the operation runs, you can save your configuration as a template and set up automation so this merge operation runs on a set schedule. If you have several templates you'd like to run together automatically, you can create a Recipe and integrate it into HubSpot Workflows.

Return to the Template menu at the top of the page and click Copy to save your configurations as a new version of the template you started with. Then click the pencil to edit your new template name.

Under Step 4, click the Review button, and select Update mode.

On the Notify tab, select the send option appropriate for your automation: Always send, Send when errors, or Do not email.

Add any additional recipients who should receive the CSV (hitting Enter after each address) and provide context in the message subject or body.

On the When tab, select Automate, and configure the frequency you'd like the template to run. When finished, click Schedule.

You can view all your scheduled automations at any time on the Operations > Automations page.

Learn More:

• Automation and Manual Operations
• Recipes
• Integrate Insycle with HubSpot Workflows

When you have a solid set of templates that reliably merge your records, you can put them together into a longer, ordered sequence as a Recipe. Then you can schedule that Recipe to run on a consistent schedule. Your templates will run one after another in the order that you set.

To add your Recipe to a HubSpot Workflow, it must be automated and set to Execute as HubSpot Workflow Action.

Learn more about integrating Insycle Recipes with HubSpot workflows.

Having your HubSpot and Salesforce CRMs set up to sync can make cleaning up duplicates tricky. You need to determine the appropriate “master record” to use across both CRMs and consider the merging process. Often, your settings in each platform impact how the merge takes place.

When you deduplicate accounts in Salesforce, the master is kept in sync with the original HubSpot record, indicated by a Salesforce Account ID value. However, the deduplication only takes place on Salesforce, leaving duplicate companies in HubSpot. Since HubSpot doesn't allow you to deduplicate companies while the sync is active from within the HubSpot app, you need another option.

Insycle allows you to merge duplicate HubSpot companies and Salesforce accounts while keeping things simple and your sync intact.

To learn more, see Deduplicate HubSpot Companies and Salesforce Accounts.

Your sales team is using both HubSpot and Salesforce and is running into problems with duplicate records in one CRM or the other, and sometimes both.

You have a data sync set up between the two systems but don't know how to deduplicate effectively to ensure the cleanup effort is consistent across CRMs. In addition, HubSpot doesn't allow you to deduplicate companies while the sync is active from within the HubSpot app.

With the Merge Duplicates module, you can flexibly merge duplicate people and companies in bulk and automatically (including through workflow automation right when visitors fill out a form) even when the HubSpot-Salesforce sync is active, and keep the master records syncing after the merge. You can also control the merge process by defining rules for picking the master record and master field values (for example, retain the owner from the contact that was created first).

To learn more, see Deduplicate HubSpot and Salesforce While Keeping the Sync Active.

When merging companies in HubSpot directly or in Insycle using the Native merge method, associated leads from the duplicate companies will appear in the master company after the merge.

When merging companies using Insycle's Synthetic merge method, special handling is applied to leads associated with those companies:

HubSpot's API prevents existing lead objects from being reassigned to different companies. This is by design—leads are meant to capture a snapshot of the specific interactions and context that led to a deal, and HubSpot preserves this by preventing lead reassignment.

Insycle's Synthetic merge can accommodate lead reassignment when merging companies. To reassign leads, Insycle automatically:

• Recreates the leads from duplicate companies
• Associates these new leads with the master company
• Maintains the original lead data: name, type, stage, and owner
• Adds a parenthetical detail to the lead name to indicate its origin (e.g., "Example Lead Name (From duplicate company Acme. Lead originally created 2025-10-02T12:52:25)")
• Replaces the original leads (so you don't end up with duplicates)

This ensures data completeness and traceability while working within HubSpot's API limitations.

  Note: If you have the Salesforce integration enabled, Synthetic merge is the default and required method for merging companies (as Native merge is not available when the sync is active). Users without the Salesforce integration can choose between Native and Synthetic merge methods in Step 3.

When deduplicating child/parent companies in HubSpot, Insycle can detect even the most complex company hierarchy associations, ensuring that the correct child company master records are associated with the correct parent company master records after the companies are merged.

Parent Company Retention: During the merge, if a duplicate company has a parent company and the master company does not, Insycle keeps the parent company from the most recently modified duplicate that has one and applies the Parent label.

Customizing Parent Company Selection: To control which parent company value is retained, configure the Parent Company field in Step 3 on the Fields tab. You can choose to keep the master's value even if it's empty, select from a record with a parent company, or base the selection on other field criteria. 

See Bulk Associate Child to Parent Companies in HubSpot for complete details.

For situations where there are no common rules you can apply for identifying duplicates for all or some of your records, you may need more granular control over which records are included or excluded from the process.

Bulk Solutions

There are two options for doing this in bulk. You can upload a CSV file of known duplicate record ID pairs directly into the Merge Duplicates module using the CSV tab in Step 1. This lets you bypass field-based duplicate detection entirely and work from a list of specific record pairs you've already identified. From there, you continue through Steps 2–4 to configure master selection rules and field retention settings, and then run the merge. 

For more complex scenarios — such as designating master records or excluding specific records from deduplication using custom attributes — you can also use the Magical Import module in combination with Merge Duplicates for complete control over the process. 

Learn how to customize merging duplicates in bulk using a CSV.

Single Record Solution

To do this one record at a time, you can use Manual mode of the Merge Duplicates module.

In Manual mode, you have complete control over which records are merged together by selecting them from the Record Viewer. Manual mode should be reserved for cases that require a careful, controlled process. Learn more about merging duplicates in Manual mode.

You have duplicate records that have been identified by Insycle but not all of them are merging into the master. 

Look at the Exclusions at the bottom of Step 3 to see how many duplicates are in the affected duplicate groups. If you have duplicate groups with more than 5 records, you may want to change the Skip duplicate groups with more than [5] records per group setting to ensure you get all of them.

This 5-record default is intended to prevent accidental merging of non-duplicate records when the filter in Step 1 is too broad.

If the Result is "Failed" and the Message column of the CSV report displays this text:

Change rules in Step 3 'Master Selection'. Failed to pick master record because multiple records (X) meet the selection criteria. In 'Master Selection', change, add, or reorder the rules such that only one record matches (if cannot determine master based on field values, use 'Record ID is lowest' as the last rule).

This means Insycle could not determine which record in the duplicate group should become the master — none of the records meet more of the rules than the others.

There are a few things you can try to resolve this:

1. Under Step 3, on the Master tab, experiment with reordering or adding rules based on fields that are likely to have unique values across your records. Think about what matters most to your business — the fields that would make one record clearly more valuable or authoritative than another. For example:

   • A field that stores an ID linked to an external system, such as an ERP, data warehouse, or proprietary internal tool — the record with that ID populated is likely the one your other systems depend on
   • The record with the highest number of associated records (contacts, deals, activities) — indicating it has accumulated more history and relationships
   • A field indicating CRM ownership or account status — for example, a record marked as "Customer" vs. "Lead," or one with an active owner assigned
   • A field that tracks revenue, subscription tier, or engagement level — the record with higher values may represent the more complete or current entry
   • A custom field your team uses to flag record quality or data source reliability

   The goal is to surface the fields that reflect record importance for your specific operations, not just default system fields.

2. Also on the Step 3 Master tab, confirm that By Priority is selected rather than Absolute.

   With By Priority, a record only needs to match one rule to be selected as master. With Absolute, a record must meet all rule criteria, which makes it much harder for any single record to qualify.

   In most cases, By Priority is the right choice. If By Priority is already selected and the error persists, none of the records in the group meet any of the criteria more than the others. Return to the Master tab and continue adding or reordering rules, focusing on the business-critical fields described in #1 above.

   

3. As a last resort, add a rule on the Master tab that uses Record ID is lowest, or Create Date is earliest. These rules will always produce a unique winner, ensuring master selection can complete even when other field-based rules cannot differentiate the records.

There are a couple of things to look at that may be causing records to be misidentified as duplicates.

First, you may need a better unique identifier. Under Step 1, if you use only fields that can correctly contain the same values across multiple records, they aren't unique identifiers. In this case, you are likely to identify unrelated records as duplicates and may accidentally merge them.

Unique identifiers are data unlikely to be shared by any other record unless they represent the same underlying entity. Common fields used for deduplication include phone numbers, email addresses, mailing addresses, and ID numbers.

Second, this may indicate the Comparison Rule under Step 1 is too broad. Try using the Exact Match comparison rule instead of the Similar Match rule. Similar Match looks for values that may be close, even with a one-character difference (e.g., a typo), broadening the search. 

Remember to always run your deduplication in Preview Mode to confirm it's working as expected before running it in Update Mode and applying the changes to your CRM records.

Most of the time, when Insycle can't find duplicates, it's because your matching rules in Step 1 aren't set correctly. However, before making any changes, verify that the fields you're using for duplicate detection are properly synced between HubSpot and Insycle.

First, check field synchronization. 

Go to Settings > Fields and make sure the Sync toggle is enabled (yellow), or the Automation box is checked for all fields you're using in Step 1.

Then, analyze matching rules. 

To analyze the underlying data and better understand how to set up your rules in Step 1, a helpful exercise is to configure your matching filters to find exact matches for only First Name and Last Name. Or for companies, you could use company name.

When you click Find, these rules can show you a broad overview of what duplicates are potentially in your database and what fields might be useful to include in your matching fields. These settings are intended for discovery purposes only and should not be used for a final merge operation, as many individuals may share the same first and last names without being duplicates. 

For more context, in Step 2, click the gear button on the right side of the title bar. Here, you can add any field from your database as a column in the duplicate group review to better understand the data in these records. These will also appear in your CSV report.

It can take Insycle a while to find and match duplicates when the fields used to identify them have very long values. The longer the values, the longer it takes Insycle to process the data and generate the results. This might come up when looking for matches based on long ID numbers, LinkedIn bio links, or other URLs with long strings attached (ex, https://www.linkedin.com/in/svadin%C3%ADr-n%C4%9Bmec-1234b31a3/).

You can speed this up by limiting how much of the value Insycle looks at.

If the beginning or ending portion of the values are all unique, you can limit the comparison to the first or last several characters using the Match Parts parameter under Step 1. 

Or use the Ignore Text (Substrings) parameter, then click the Terms button.

On the Ignored Text tab of the popup, add the common portion of the URL or text string.

If you see the following error for a HubSpot record after you run an operation:

“Cannot merge object [ID] in portal [ID]. It already has more than 250 objects merged into it.”

This suggests that too many duplicates are trying to merge into a single record.

What’s Happening

HubSpot enforces a strict limit on merges. A contact, company, or deal cannot have more than 250 merged records associated with it. HubSpot tracks all previous merges using the read-only property called Merged Record IDs. When a record has already reached (or will reach) 250 merged items, HubSpot blocks any further merges. There is no way to clear or edit this field, or to bypass the limit in the HubSpot app.

Solution

As a workaround, you can switch to Insycle’s Synthetic Merge. In the Merge Duplicates module, go to Step 3 and select the Method tab. Switch the Merge API option from Native to Synthetic. If this is a template, don't forget to save. 

For more details, refer to this Native Merge vs. Synthetic Merge info.

If you're having issues with your HubSpot properties missing or not working as expected during merge duplicate operations, it could be due to field inclusion settings or read-only fields.

Issue 1: Field Inclusion Settings

Fields must be included in your Insycle dataset to be available throughout the application.

To check and enable field inclusion:

1. Navigate to Settings > Fields
2. Select your database and object type from the top menu
3. Use the search to find the field you need
4. Verify that the Included toggle is enabled (yellow = on, grey = off), or the Automation box is checked
5. If not, toggle the Included control to the 'On' position

Learn more about managing the HubSpot fields included in Incycle.

Issue 2: Read-Only Field Restrictions

If a field is included but still doesn't appear in the Fields tab under Step 3, it may be a read-only field.

Field rules in Step 3 can only update writable fields. Read-only fields are not shown in the Fields tab dropdown because HubSpot prevents these properties from being written back. Insycle excludes them from the field selection options to prevent errors.

Where you CAN use read-only fields:

• Master tab (Step 3): Use read-only fields like "Last Activity Date" to make merge decisions without attempting to modify those properties
• Step 1: Use for filtering and matching duplicates
• Step 2: Review data in the Record Viewer
• CSV reports: Include as columns for analysis

Where you CANNOT use read-only fields:

• Fields tab (Step 3): Cannot create field retention rules for read-only properties

To identify which fields are read-only:

1. Navigate to Data Management > Cleanse Data
2. Search for a specific field by name, or click the Writable heading in the table to sort and review all writable or non-writable fields
3. A checked box in the Writable column indicates the field is writable; an unchecked box means it is read-only