Contact Sync matching and duplicate contacts

This article explains how Sync 365 matches Microsoft 365 users to PSA contacts, why duplicate contacts can appear, and what to check if contacts are not updating as expected.

How Contact Sync works

Contact Sync uses Microsoft 365 as the source of truth and updates supported PSA contact records from Microsoft 365 user information.

Depending on your configuration, Sync 365 can:

• Create contacts in the PSA from Microsoft 365 users.
• Update existing PSA contacts.
• Mark previously matched contacts inactive when the Microsoft 365 user becomes inactive or is removed.
• Map contacts to specific PSA sites or locations using filters.

How contacts are matched

Sync 365 primarily matches contacts using email address. This means clean and consistent email addresses are important.

If a Microsoft 365 user email matches an existing PSA contact email, Sync 365 can link to that contact instead of creating a new one.

Why duplicate contacts can appear

Duplicate contacts usually happen when Sync 365 cannot confidently match a Microsoft 365 user to an existing PSA contact.

Common causes include:

• The PSA contact has a different email address from Microsoft 365.
• The PSA contact is missing an email address.
• The Microsoft 365 UPN is different from the user’s actual email address.
• The same person has multiple contact records in the PSA.
• The user is mapped to a different PSA site/location than expected.

Important setting: Update existing contacts

The Update existing contacts option controls whether Sync 365 should update contacts that already exist in the PSA.

Recommended setting: enable Update existing contacts when you want Sync 365 to maintain contact details from Microsoft 365.

If this setting is disabled, Sync 365 may match existing contacts but not update their details. It may also limit how inactive contact handling works.

Blank fields in Microsoft 365

Blank Microsoft 365 fields should not overwrite existing PSA values.

For example, if a PSA contact already has a job title but the Microsoft 365 user title is blank, Sync 365 should not remove the existing PSA title just because Microsoft 365 has no value.

What information Sync 365 can update

Common synced fields include:

• First name
• Last name
• Email address
• Phone number
• Mobile number
• Title

The exact available fields can vary depending on the PSA and the data available in Microsoft 365.

How to troubleshoot duplicate contacts

1. Open the affected company in Sync 365.
2. Review the Contact Sync configuration.
3. Confirm whether Update existing contacts is enabled.
4. Check the Microsoft 365 user email and UPN.
5. Check the PSA contact email address.
6. Look for multiple PSA contacts with the same or similar name.
7. Check Contact Sync filters and site/location mapping.
8. Correct the PSA contact email or Microsoft 365 email if needed.
9. Run Contact Sync again or wait for the next scheduled sync.

How to avoid duplicate contacts

• Clean up existing duplicate contacts in the PSA before enabling Contact Sync broadly.
• Make sure PSA contacts have accurate email addresses.
• Use the user’s real email address rather than an old alias where possible.
• Enable Update existing contacts when Sync 365 should manage existing records.
• Use Contact Sync filters carefully when mapping contacts to PSA sites or locations.
• Test Contact Sync on one or two customer companies before enabling it widely.

Contacts not being marked inactive

If Microsoft 365 users are removed, disabled, or no longer licensed, Sync 365 may mark previously matched PSA contacts inactive depending on your configuration.

If contacts are not being marked inactive, check:

• The contact was previously matched by Sync 365.
• Update existing contacts is enabled where required.
• The Microsoft 365 user is no longer active or licensed.
• The PSA contact email still matches the Microsoft 365 user record that was synced.
• The contact is not excluded by filters or site/location rules.

Contacts going to the wrong PSA site or location

If contacts are being created or updated under the wrong PSA site/location, review your Contact Sync filters.

Filters are applied in priority order. More specific filters should generally be placed above broader catch-all filters.

For example, if you have a department-specific filter and an “all licensed users” filter, the department-specific filter should normally be above the broader all-users filter.

When to contact support

Contact support if:

• Sync 365 is creating duplicate contacts even though email addresses match.
• Contacts are not updating after settings are confirmed.
• Contacts are not being marked inactive when expected.
• Contacts are being assigned to the wrong PSA site/location.
• You are unsure whether to enable Update existing contacts.

When contacting support, include the company name, Microsoft 365 user email, PSA contact email, screenshots of the Contact Sync settings, and examples of the duplicate or incorrect contacts.

Related articles

• Microsoft 365 Contacts to PSA Contact Sync
• Create shortcuts from PSA direct to Sync365 company
• Conditional Access Policies
• Checking your GDAP relationship