Prevent Duplicate Submissions with the Unique Setting

Form owners sometimes request help to limit their visitors to one result per person. Formsite has a few ways to prevent duplicate results to keep their Results Tables tidy. These built-in functions help to prevent cheating, block spammers, and other useful tasks, too.

Some places to prevent duplicate entries include:

• Tests or quizzes to prevent repeating
• Surveys to avoid skewing results
• Auctions to prevent artificially inflating the bids
• Orders to prevent accidental or intentional duplicates
• Registrations to prevent double-booking

Prevent Duplicate Results

The most effective way to prevent duplicates is to choose a required item and set its Unique setting. The Unique setting looks through every result in the Results Table for the same value, then returns an error message if it’s already there.

Using the Unique setting with the Email Address item works the best, though other items work as well. Applying the setting on the visitor’s ‘last name’ item would prevent more than one result for the entire family, for example.

Take care, however, in case there are more than one family with the same last name. Other items that can be unique would include neighborhoods, picking teams, auction amounts, etc.

The Prevent Multiple Submissions Setting

The Form Settings -> General -> Security page contains a setting to Prevent Multiple Submissions Per User. This setting works differently than the Unique setting in that it helps to prevent accidental duplicate submissions.

Enabling this setting sets a cookie on the visitor’s browser and prevents the same form from submitting from that specific browser. Using a different browser or clearing the browser’s cookies allows the visitor to easily work around that setting. Since the Unique setting works entirely in the background, we recommend using that instead.

Save & Return

Another way to prevent duplicates is to use the Save & Return feature. That lets form visitors create accounts on the form to complete the form over multiple visits. If the visitor doesn’t remember if they’ve submitted the form, logging in will show any previous results.