> For the complete documentation index, see [llms.txt](https://docs.zero.inc/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.zero.inc/settings/merging-duplicates.md).

# Duplicates

Duplicates creep in through imports and agents however careful you are, and the damage is that half a relationship's history ends up on a record nobody opens. Merging fixes that without losing anything — you can do it from workspace settings, straight from a list, or by asking Chat.

## How to find and merge duplicates

{% stepper %}
{% step %}
Go to **Settings → Data → Duplicates** (admin only).

<figure><img src="https://storage.googleapis.com/zero-production-api-docs/images/duplicates_settings_nav.png" alt="Duplicates settings on the Companies tab with match-key options, a merge toolbar and a no duplicates found message"><figcaption></figcaption></figure>
{% endstep %}

{% step %}
Zero scans the workspace and shows **Companies**, **Contacts** and **Deals** with the number of duplicate groups in each. A group is records sharing the same value for the match key, which you choose with the **By:** switch:

* **Companies** — **Domain** (default), **Name**, **LinkedIn**, or **External ID**
* **Contacts** — **Email** (default), **Name**, **LinkedIn**, or **External ID**
* **Deals** — **Name** (default) or **External ID**

Matching on **Domain** or **Email** looks at every domain a company owns and every address a contact can be reached at, not just the primary — so a company whose secondary domain is another's primary still surfaces. **Search duplicates...** narrows the groups.

<figure><img src="https://storage.googleapis.com/zero-production-api-docs/images/duplicates_match_key_switch.png" alt="Duplicates tab bar for companies, contacts and deals above the match key switch for Domain, Name, LinkedIn and External ID"><figcaption></figcaption></figure>

<figure><img src="https://storage.googleapis.com/zero-production-api-docs/images/duplicates_deals_section.png" alt="Duplicates Deals tab with a Name and External ID match switch and one duplicate group of two deals ready to review"><figcaption></figcaption></figure>
{% endstep %}

{% step %}
Click **Review** on a group. The merge dialog shows each record with its company, contacts, deals and lists, and when and by whom it was created. Click **Keep** on the one that should be the **main record** — data comes from all of them, but the main record wins any conflict. See [#what-gets-merged](#what-gets-merged "mention").

<figure><img src="https://storage.googleapis.com/zero-production-api-docs/images/merge_contacts_pick_keep.png" alt="Merge Contacts dialog showing two duplicate contacts with their company, deals, and lists, and an arrow pointing to a Keep button" width="563"><figcaption></figcaption></figure>
{% endstep %}

{% step %}
Click **Confirm Merge**.
{% endstep %}

{% step %}
You can review the consolidated records in any list.

<figure><img src="https://storage.googleapis.com/zero-production-api-docs/images/merged_contact_result_row.png" alt="Merged contact row in a list showing the combined company, email, two deals, and list membership"><figcaption></figcaption></figure>
{% endstep %}
{% endstepper %}

## Merging from a list or from Chat

When you already know which records are duplicates, skip settings entirely.

* **From a list** — select two or more records of the same type and click **Merge records** in the toolbar at the bottom. Same dialog: pick **Keep**, then **Confirm Merge**.
* **From Chat** — "merge the two Acme companies, keep the one with the website". [Chat](/getting-started/chat.md) finds them, confirms which survives, and merges. The same is available over [MCP](/developers/mcp.md) and through the [Merging Records](/developers/api/merging-records.md).

The result is identical however you start it.

## What gets merged

* Everything is combined into one record.
* Where fields conflict — two different cities in **Location**, say — the **main record** wins, custom properties included. Where the main record is empty, identity fields such as name, company, location, LinkedIn and phone are filled from the duplicates.
* **Owners** and **lists** from all original records are combined, and notes written on the record page are appended together.
* **Company domains** and **contact email addresses** are not discarded: every domain across the merged companies ends up in the company's **All Domains**, and every address across the merged contacts ends up in the contact's **All Emails**. The main record's value stays the primary **Website Domain** / **Email** — the one used for sending.
* Related records are re-linked to the main record instead of being lost:
  * **Contacts**: deals, email threads, calendar events, LinkedIn conversations and connections, custom activities, tasks, notes, comments, files, invoices, issues, and analytics events.
  * **Companies**: contacts, deals, email threads, calendar events, and other related records.
  * **Deals**: email threads, calendar events, custom activities, tasks, notes, comments, and files.
* If any merged contact was unsubscribed from all messaging, the merged contact stays unsubscribed.
* The duplicates are archived and marked as merged into the main record — they are not permanently deleted.

## Bulk merge

For a backlog rather than a handful, use the toolbar above the groups:

1. Tick the checkboxes on individual groups, or use the select-all checkbox.
2. Use the **Keep:** switch to decide which record in each group becomes the main record — **Oldest** (default) or **Newest**.
3. Click **Merge selected** (or **Merge all** when everything is selected).

Anything that fails is flagged with a warning icon for you to review one by one.

<figure><img src="https://storage.googleapis.com/zero-production-api-docs/images/duplicates_bulk_merge.png" alt="Duplicates merge toolbar with two groups selected, a Keep oldest or newest choice and an active Merge all button"><figcaption></figcaption></figure>


---

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