With a predefined form, allow for sending field data to the form that already exists where the user only needs to fill out the missing information or change incorrect information. Then have that field data sent back to a server that can store the completed record in a database.
In the medical field this could be precheck-in patient information where the patent is verifying their existing record and adding new information about this visit.
In the mortgage field this could be forms where a quarter of the information is repeated on each form but there is additional information that also needs to be filled out.
This kind of form workflow would allow many that use Word forms or PDF forms today on a client workstation to be able to do the same in a web application with little technical integration.