---
title: "Unique for Merging"
slug: "unique-for-merging"
updated: 2026-03-18T15:31:30Z
published: 2026-03-18T15:31:30Z
---

> ## Documentation Index
> Fetch the complete documentation index at: https://knowledge.technolutions.net/llms.txt
> Use this file to discover all available pages before exploring further.

# Unique for Merging

You can create [custom text fields](/v1/docs/fields-that-store-free-text-values) that store **external IDs**or other unique, record-specific values.

You can use these external IDs when data comes into Slate—through an [import](/v1/docs/importing-data-overview)or a [form](/v1/docs/forms) submission—to match the incoming record to an existing one in your database. These fields play a critical role in integrations, like when you import data from external systems with unique system IDs into Slate.

## The Unique for Merging setting

When you create a new field, you’ll find a setting in the Details tab called **Unique for Merging**.

For text fields, the default value for this setting is `Do not use value for merging`*.*

When you change this value to `Value contains a unique ID which identifies a single record for merging`, Slate uses the incoming field’s value to match against existing records in its scope.

[![Unique for Merging Setting](https://cdn.us.document360.io/cd8ea7a6-07f3-4846-a554-627ac016d3e3/Images/Documentation/10273366392475.png)](https://cdn.us.document360.io/cd8ea7a6-07f3-4846-a554-627ac016d3e3/Images/Documentation/10273366392475.png)

## Example unique for merging fields

Say you have a nine-character text field called `Unique ID`.

If a record has a value of `123456789` in this field, and its unique for merging setting was set to `Value contains a unique ID which identifies a single record for merging`, **no other record in that dataset could have that same value.**

If another record entered the Dataset that had this field set to a value of `123456789`, Slate would **merge**that record with the existing record with that value.

> [!WARNING]
> **📝 Note: 64 character limit for unique for merging fields**
> 
> Slate only evaluates the first 64 characters of the values of incoming unique for merging fields. Values greater than 64 characters may result in unexpected behavior.

## Unique for merging and Consolidate Records

The **Consolidate Records tool**uses unique for merging fields to find potential matching records.

Configure a custom, unique for merging field only if each record is guaranteed to have a unique value for the field.

Examples of unique custom fields include:

- SIS ID
- Banner ID
- EmplID
- ColleagueID
- CommonApp ID
- Questbridge ID

📖 **Further reading:** [Consolidate Records](/v1/docs/consolidate-records-and-the-effects-of-main-vs-duplicate)

## Mapping data imports to multiple unique for merging fields

**Exercise caution when you map data imports to multiple unique for merging fields.**The import may use *any*of the unique for merging fields to match a candidate application or person.

Similarly, collecting values publicly (that is, through a public-facing form) to unique for merging fields can result in record collisions if transcription errors occur.

Slate has a clearly-defined hierarchy of criteria by which it matches records. Knowing how this works will help avoid unexpected behavior on record imports.

#### 📖 Further reading: matching criteria

Learn more about matching criteria as they relate to different kinds of objects in these articles:

- [Matching Criteria for Application Records](/v1/docs/matching-criteria-for-application-records)
- [Matching Criteria for Person Records](/v1/docs/matching-criteria-for-person-records)
- [Matching Criteria for System Objects](/v1/docs/matching-criteria-for-system-objects-schools-tests-interactions-and-more)