How can you populate subform key fields automatically based on the related Main form's key field, when the key is not an autonumbered field? Simple parent/child relationship, the 'link master fields' and 'link child fields' are set correctly, and have done it plenty of times fine with autonumbered fields. The problem now is that the primary/foreign key is not an autonumbered field, just a value the user types in that is unique. After filling the primary key value correctly in the main form and then trying to enter in an associated record in the subform, the key isn't automatically filled in for the child record. What am I missing?