We are using Cognito Forms for a survey and would like to prevent a single person from submitting the questionnaire more than once.
Does Cognito Forms offer a function or option like this, and if so where/how do I set this?
There is no feature to do this automatically. You can capture the ip address of the submitter in the entry (see here). That at least would let you discard additional submissions from the same source after the fact.
Add a username column to the form.. and using some js you can check if that username is already present then that particular user is not allowed to fill the form
