Preventing duplicate entries by respondents

Good day, everyone,
I am developing a form which i will use to collect data on IDs.
I don’t want respondents to enter the same information more than once.
If the respondent want to enter the same information, the system should not allow the second submission.
I need help
thank you

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:

Data entry screen as seen in Enketo (when the record is already present in the server):


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 project to itself.

Failing to achieve these points will affect what you have planned. For more details, please feel free to go through our support article:


Hi Kal_Lam,
Could you please make more clear about “To make this work, you must link the project to itself”. I enable “Data sharing enabled”. then in the same form, I imported itself (select phone number that I want to validate the duplicate), but it do not work. thanks
My register form

my setting of this form in kobo

my form

when I try to enter the same phone number, Kobo could not find the duplicate.

Please help

@win123vn, your configuration seems to be OK. You will need to wait for 5 minutes (syncing time) to get the dynamic data working.

thanks @Kal_Lam for replying, I will test again.

Dear @Kal_Lam ,
I am found that is a good solution for this discussion but it seem took too long to wait for doing the survey.