The gf_unique merge field helps you prevent respondents from taking your survey more than once.
To add gf_unique to your survey and prevent duplicate responses:
When you pass the gf_unique merge field value into your survey, the respondent with that identifier won’t be able to submit additional responses.
Combine gf_unique with other merge fields to prevent duplicate responses, track each respondent, or personalize the survey experience.
You can use any parameter you'd like to identify respondents. If you use Email address to identify respondents your survey link might look like this:
To prevent a contact from leaving a duplicate response and attach an email address, add the Email merge field. When you add two merge fields, your survey URL will have each merge field separated by an & symbol:
Combine as many merge fields as you like. Pull in the respondent's name, email address, contactid, or their country code, in addition to using gf_unique.
The gf_unique merge field will only prevent responses after someone completes your survey gf_unique can't prevent duplicate incomplete responses. Once the respondent has completed the survey, opening the survey again after they’ve already completed will lead them to this page that reads "Your response for this survey has already been recorded."
If you have branding applied to your GetFeedback account or survey, the landing page will show the survey background image or color with the same message.