This is the City of Boston Real Estate Tax payment page:
www.cityofboston.gov/realestate/
This Form asks for a "Parcel ID (10-digit number)"
But on the Tax Bill you have:
WARD (2 digits)
PARCEL NO. ( 8 digits with an embedded "-" ).
The form should ask for you to enter your Ward AND Parcel ID.
It should also programatically remove the "-" is people enter it.
Note: The helpful PARCEL ID description is no where near the data entry field.