The codes USED to be on the booklet that came along with the Tax Return. However, since they don't send the booklet / tax returns any longer, people who don't use the computer software are forced to "ask around" until they find the proper codes.
All of the codes are listed on the PA website below (My wife is a CPA so she knows right where to track them down):
Just click on the link for: PA School Districts and Codes By County (.PDF)
Then look up your school district under BUCKS COUNTY.
PS. Morrisville Boro code is 09720
Hope that helps.
Brian Luce ABR, SRS
Weidel Realtors - Doylestown
215-348-5600 x 163