Siddha Ruth
I did d not see your post until now.
T native way to do this is actually quite simple.
Relationship between contracts and amendments you make a summary field of the maximum of the amendment number.
Then you look that up down to the child record.
Can you create a snapshot field. A snapshot feel takes the value of the look up at the moment it is created and Fries is it like a snapshot photograph. To set up a snapshot field he would set up a simple numeric field but at the very bottom of the field properties you tell it to be a snapshot field
So then you just have a formula that the amendment number for that record is the snapshot field plus one.
