Length constraint for numbers

[Kal_Lam]

Welcome to the community, @Mauro_Nharreluga! Have you tried this workaround discussed previously? It should solve your issue:

I am trying to limit the response to have 9 numbers for ID

Maybe you could do the same as outlined in the image shared below: In the survey tab of your xlsform: [Image 1] Data entry screen as seen in Enketo: when a wrong entry is made [Image 2] Data entry screen as seen in Enketo: when a correct entry is made [Image 3] Reference xlsform: Number (Regex).xlsx (10.2 KB)