Can people go back later and change their form submissions?

Also, can people go back later and change answers.

Yes, it is possible to allow users to update their form submissions at a later date. We have a guide on that here: https://www.jotform.com/help/40-How-to-Let-Users-Update-Their-Form-Submissions-at-a-Later-Date

I hope this helps. If you need further assistance please let us know. Thank you.