some time ago the following question was raised in this Community
" I'm wondering if it is possible to get the "settlement period" and / or the "settlement start & end date" of the service contract billing plan item to the billing invoice? It is a legal requirement to print these dates on the billing form. If this is not possible, what is your recommended workaround here? Is it possible to create an custom field which can be transferred to the invoice via copying control?"
My colleagues from development support created an useful document to get this requirement. I've just uploaded it Extensibility_contract & Billing form printout