Data Loader/Data Import Wizard Adds "Invalid Values" to Picklist

Overview

This is the expected behavior based on standard Salesforce functionality. When the picklist restriction setting is disabled, Salesforce accepts values not defined by the administrator and adds them to the picklist as "Invalid Values."

Cause

If the "Restrict picklist to the values defined in the value set" checkbox is unchecked (disabled) in the picklist field settings, Salesforce accepts any imported value — even one not defined by the administrator — and adds it to the picklist field as an "Invalid Value."

Solution

To prevent data other than the defined values from being imported, enable the restriction using the following steps:

1. Click Setup | Object Manager.
2. Select the target object and click Fields & Relationships.
3. Click the target picklist field.
4. Click Edit.
5. Check the box for "Restrict picklist to the values defined in the value set."
6. Click Save.

Enabling this setting causes an error when you attempt to import or update records containing an undefined picklist value, preventing unintended values from being added to the system.