How to constraint anonymous user to submit the form only once?

[Kal_Lam]

@alan_luqman, if that is the case then try the Dynamic Data Attachment feature as outlined in this post discussed previously:

Preventing duplicate entries by respondents

Welcome to the community, @nkwantanorth! You could do this by exploiting the dynamic data attachment feature as shown below: In the survey tab of your XLSForm: [image] Data entry screen as seen in Enketo (when the record is already present in the server): [image] Reference XLSForm: Beneficiary Name Check (Case Management).xlsx (9.4 KB) Please note the following when using the Dynamic Data Attachment feature to work: It takes 5 minutes to sync the data To make this work, you must link the …

But, please be sure that the syncing time is 5 minutes. If you try to submit a record within the 5 minutes syncing time users are able to submit another record too.