Follow the below steps to create a formula field that will give you the 18 characters ID of the records.
- Go to Setup | Customize | object name | click Fields
(For Custom objects: Setup | Create | Objects | Object Name)
- In the related list “Custom Fields & Relationships” click New.
- Click the Formula radio button.
- Click the Text radio button for “Formula Return Type”.
- 6. Input the following Formula into the Formula Editor:
- Set Field Visibility, add/ remove from Page Layout(s).
- Click Save.
NOTE: When dealing with record types only custom record types have ids.