Hi Lee, good question. If you make a form and you have a primary Id field in it then you must have a corresponding field in your subform table only it will not be an autonumber field in the subform - it will be a number field. If the field in your subform table has the same name as the primary field in your main table then Access will make the relationship for you. If you need more info, please let me know.  John

Thank you John.