Hi Vallabh
Usually, it is populated in the "Note to Payee" section. The note to payee comes under each vendor record in the file
But you are using it has to be part of Header.. So, try to increase the field length of the existing field and see if you can get more characters.
Else, put a user exit in this node and populate the details from User Exit
Please close your issue once resolved. I hope you will do that starting from this thread. How to close a discussion and why
Ajay M