By default, applicants can update a submitted application right up until the deadline. You can prevent editing a submitted application by selecting the Applications locked after submission option from Settings > Applications > General.
With this setting applied, applicants will be able to view but not edit their application.
Can a submitted application be changed to in progress?
Yes! Should the applicant need to update information within their application for whatever reason, a grant manager can return the application to an in progress state by following the steps outlined in our guide here: Revert an application to in progress.