> This page is for Docs.

> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://zuora.ferndocs.com/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://zuora.ferndocs.com/_mcp/server.

# Create legacy custom fields

> Learn how to create a legacy custom field for a standard object.

Learn how to create a legacy custom field for a standard object.

Open the settings page:

* If the object is related to accounts, subscriptions, invoices, or products, click your username at the top right and navigate to **Billing settings**.
* If the object is related to payments or refunds, click your username at the top right and navigate to **Payments settings**.
* If the object is related to accounting or revenue, click your username at the top right and navigate to **Finance settings**.

Click **Manage Custom Fields**.

Select the object for which you want to created the custom field.

In the **Indexed** or **Non-Indexed** group, click **Add New Field**.

Select a field type, then enter the field definition. You must make sure every Picklist value is unique when you fill in **Picklist Values**. The picklist value is case-insensitive. For example, "Business" and "BUSINESS" are treated as the same value and cannot both be added. There is no limit on the number of values for a picklist-type field. If you select **Required**, Zuora will require users to specify a value for the field when creating an object. If you select **UI Read Only**, users will be able to update the field's value via the Zuora API but not via the Zuora UI.

> **Note**
>
> The suffix `__c` (two underscores and the letter "c") is automatically appended to the end of the API name when Zuora creates the custom field.

Click **Save**.

When custom fields are created, they are available in the corresponding object detail pages in the Zuora UI or through the respective API operations.

When Zuora creates a custom field, Zuora does not apply the default value to existing objects. This means that if you define a custom field, then immediately perform a ZOQL query such as `select BetaTester__c from Account`, the query will not return any values for `BetaTester__c`.

To apply the default value to an existing object, you must modify the object via the Zuora UI or the Zuora API.