Enable More Than 20 Fields For Field History Tracking.

This approach uses a custom Text field which stores values of multiple other individual fields. Then enabling field history tracking of this field would allow you to track changes for multiple sets of other individual fields, instead of enabling field history tracking for 3 fields – Email, City, Phone- the only field which needs to be enabled for history tracking is the custom field – track3Fields.

This way you are able to track changes for 3 fields by consuming only 1 unit of the total 20 limits.

Step 1: Add a new custom field.

Setup -> Create -> Objects-> Incident

Create a new Text (255) field “track3Fields”

Step 2: Create a workflow on Incident object with the following:

Event: On Create/Update

Criteria: On any change of Email, City, Phone

Action: Field Update

Set track3Fields = Formula (Email: <Email> + City: <City> + City: <City>)

Step 3: Enable Field History tracking for this combined field “track3Fields”.