---
title: "Require unique entries in fields"
slug: "requiring-unique-entries-in-fields"
updated: 2026-04-29T16:59:34Z
published: 2026-04-29T16:59:34Z
canonical: "help.quickbase.com/requiring-unique-entries-in-fields"
---

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

# Require unique entries in fields

There are certain fields that you never want to contain duplicate values. This might be a field containing the Employee ID or Invoice Number. You can prevent a field from having duplicate values by making it unique. In other words, for each record, the value in the field must be different.

A field can be marked as unique when it:

- Doesn't contain a reference to the record ID#
- Doesn't contain a reference to a dynamic function
- Is not a list-user, list-text, phone, or address field
- Follows the criteria listed in [Limits in Quickbase](/v1/docs/limits-in-quickbase#quickbase-feature-limits)

## To require unique values in fields

You can require unique values using either field settings or [Visual Builder](/v1/docs/visual-builder).

### Use field settings to require unique values

1. [Open the field's properties page](/v1/docs/change-the-properties-of-a-field-from-a-legacy-form).
2. In the **Basics** section, select the **Must be unique** checkbox. You can also check for existing duplicate, non-unique values by selecting **Check existing entries for duplicate values**:

![Field properties page showing the Basics section with Must be unique and Check existing entries for duplicate values checkboxes](https://cdn.document360.io/dd260e4e-10bb-4b66-8fb3-5504c272b904/Images/Documentation/4572878699668.png)
3. Select **Save**.
4. If you selected to check existing entries, a message appears if there are any duplicates and **Must be unique** is de-selected. You can:
  - Edit existing records to make corrections as necessary, return to the field properties page, then try steps 1-3 again.
  - Select only **Must be unique** if you decide it doesn't matter that existing data in this field is unique, or if you want only new entries in this field to be unique.

### Use Visual Builder to require unique values

1. Open a table, select **Settings**, then select **Structure**. Visual Builder opens with the table expanded.
2. Select the field you want to appear in bold, then use the field properties on the right to select the **Must be unique** checkbox:

![Visual Builder showing a field selected with the Must be unique checkbox in the field properties panel on the right](https://cdn.document360.io/dd260e4e-10bb-4b66-8fb3-5504c272b904/Images/Documentation/4572864212500.png)
3. All changes are saved automatically.