Considerations and Activation of "Create Audit Fields" in Salesforce

What Is the Create Audit Fields Feature?

Salesforce allows system fields to be set through the API during data migration. When migrating data from an external system, the API lets you set a number of fields on objects that were previously read-only. By setting these fields, records appear to have been created at the time they were originally created on your old system.
Since these fields are intended to be Audit Fields, they can only be set on create (INSERT) and not on update. If the records already exist in Salesforce, they must be exported to a CSV file, deleted in Salesforce, and then imported with the updated information as new records.
Salesforce recommends enabling this feature only during data migration. In certain cases, such as routinely copying new data from an external system to Salesforce, this can be enabled permanently. This feature must be enabled by a System Administrator.

Important Considerations

• Create Audit Fields is a generally available feature. A Salesforce Support video is available that demonstrates the feature. The video covers how to enable Create Audit Fields in Setup, how to set audit field values using the API during data migration, and how to perform a Data Loader import using the CreatedDate field.
• This feature does not permit values to be updated, only inserted (this only works for INSERT, not UPSERT).
• The LastModifiedDate and LastModifiedBy fields will not reflect the inserted value if a Task is associated with a Contact or Lead (WhoID) or other records such as Account, Opportunity, or Campaign (WhatID) during Task Insert.
• Permission required to set audit fields: Modify All Data.
• When Enhanced Email is enabled and EmailMessages are inserted, the associated Task records auto-created will not use the CreatedDate of the EmailMessage — they will have a CreatedDate of the date of insertion.