Fix Duplicate Salesforce Leads and Contacts in Hubspot

When Salesforce leads or contacts sync incorrectly, you can end up with duplicate records in Hubspot that confuse reporting, segmentation, and automation. This guide explains the most common reasons for duplicates and the exact steps to diagnose and fix them using the Salesforce integration.

How the Salesforce–Hubspot Sync Works

Understanding how the integration links records is critical to preventing duplicates. Hubspot and Salesforce use a combination of internal IDs and email addresses to keep data aligned across both systems.

At a high level:

• Salesforce leads and contacts sync to Hubspot contacts.
• The integration uses a hidden Salesforce ID field stored on the Hubspot contact.
• Email address is also used by Hubspot to match or create contacts when no existing match is found.

When the internal IDs or email addresses do not match as expected, duplicates can appear on either side.

Primary Causes of Duplicate Contacts in Hubspot

Several scenarios can cause multiple contacts to appear in Hubspot even though Salesforce appears to have only one person. Below are the most frequent causes and how to spot them.

Cause 1: Edited or Changed Salesforce IDs

Each Salesforce lead and contact has a unique internal ID. The Hubspot Salesforce connector stores these IDs on the Hubspot contact record to maintain the link between platforms.

If this Salesforce ID is changed or overwritten in Hubspot, the connector may assume it is a different person and create a brand‑new contact on the next sync.

Common ways this happens:

• Bulk updates that overwrite the Salesforce ID property in Hubspot.
• Custom integrations or workflows that manipulate the ID field.
• Incorrect imports that map external values into the Salesforce ID property.

When this happens, you can see two or more contacts in Hubspot representing the same prospect or customer, but only a single record in Salesforce.

How to Diagnose an ID Issue in Hubspot

1. Open the duplicated contact records in separate browser tabs.
2. Compare the Salesforce Lead ID and Salesforce Contact ID properties on each Hubspot contact.
3. Check whether the IDs match the corresponding record in Salesforce.
4. If one Hubspot contact has no Salesforce ID or a clearly incorrect one, that contact is likely the duplicate.

Once identified, you can merge the Hubspot contacts and preserve the correct link to Salesforce.

Cause 2: Email Address Changes in Salesforce

Email address is another key field used for matching. If a user edits the email in Salesforce, the integration could treat the updated value as a new person and create a fresh Hubspot contact.

Symptoms of this problem include:

• Two Hubspot contacts with different emails but the same name and company.
• One Hubspot contact linked to the Salesforce lead, another not linked at all.
• Recent activity showing a new contact created soon after an email was updated in Salesforce.

The original Hubspot contact may remain connected to Salesforce, while the new contact is created purely from the updated email data.

Diagnose Email‑Based Duplicates in Hubspot

1. Search Hubspot for contacts using the person’s first name, last name, and company.
2. List all matching contacts and compare their primary email addresses.
3. Check the Salesforce Lead ID or Contact ID fields to see which contact is actually connected.
4. Confirm in Salesforce whether the email was recently changed.

If you confirm that both Hubspot contacts represent the same person, merge them and ensure that the final record retains the correct Salesforce ID.

Preventing Future Duplicates in Hubspot

Once you have cleaned up existing duplicates, you should harden your process so they do not reappear. The following practices help keep your Salesforce and Hubspot data aligned.

Best Practices for Salesforce ID Integrity

• Never map external values into Salesforce ID properties during imports to Hubspot.
• Restrict who can edit Salesforce ID properties in Hubspot to administrators only.
• Review any custom integrations to ensure they never modify these ID fields.
• Audit bulk updates and workflows that touch system properties before running them at scale.

Maintaining a clean one‑to‑one relationship between Salesforce IDs and Hubspot contacts is the most effective way to avoid duplicates.

Best Practices for Email Management Between Salesforce and Hubspot

• Encourage users to update email addresses only in one system (typically Salesforce) and let the integration push changes to Hubspot.
• Avoid creating new leads in Salesforce for people who already exist as contacts; convert them instead.
• Use validation rules in Salesforce to prevent trivial or test emails that might add noise to Hubspot.
• Monitor recent contact creations in Hubspot to quickly spot suspicious duplicates after major data changes.

How to Clean Up Existing Duplicates in Hubspot

When duplicates already exist, a structured cleanup process will help you preserve history and keep the right record synced with Salesforce.

Step 1: Identify Duplicate Clusters

1. Use the duplicate management tools in Hubspot (such as contact duplicate suggestions).
2. Filter contacts by name, email, or company to find clusters that look identical.
3. Export a list of suspected duplicates for review if you are working at scale.

Step 2: Decide on the Master Record in Hubspot

For each duplicate cluster:

• Choose the Hubspot contact that is correctly linked to Salesforce via a valid Salesforce ID.
• Check which record contains the most accurate and complete property values.
• Confirm that the master record has the correct email address and subscription details where applicable.

Step 3: Merge Duplicate Contacts in Hubspot

1. Open the master Hubspot contact.
2. Use the merge function to combine the duplicate into the master.
3. Verify that activity history, notes, and form submissions are preserved after the merge.
4. Confirm that the Salesforce sync continues to run without creating a new duplicate.

If you manage a large number of duplicates, consider building a repeatable internal process or engaging a CRM specialist.

Troubleshooting Complex Duplicate Issues

Some duplicate scenarios involve a mix of edited IDs, email changes, and legacy data from earlier integration configurations. When simple merges are not enough, you may need a more detailed review of your Salesforce and Hubspot mapping.

For complex environments, you can:

• Review the full integration settings and field mappings.
• Check integration logs to see when and how records were created or re‑synced.
• Temporarily pause specific sync rules while you perform bulk clean‑up.
• Document standard operating procedures for sales and marketing teams to follow.

You can find the official integration behavior and edge‑case details in the original Salesforce duplicate documentation here: Salesforce duplicates and Hubspot sync.

Get Expert Help Optimizing Your Hubspot–Salesforce Setup

Keeping Salesforce and Hubspot aligned is essential for accurate reporting, lead routing, and automation. If your team is struggling with recurring duplicates, mis‑mapped properties, or inconsistent sync behavior, a specialist review can save hours of manual clean‑up.

For advanced integration audits, custom field strategies, and data hygiene projects, you can work with a dedicated CRM partner such as Consultevo to design a scalable approach.

By protecting your Salesforce IDs, managing email updates carefully, and following the structured merge steps in this guide, you can dramatically reduce duplicate contacts in Hubspot and maintain a reliable, unified view of every lead and customer.

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