> For the complete documentation index, see [llms.txt](https://docs.epicollect.net/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.epicollect.net/formbuilder/double-entry-verification.md). # Double-entry Verification To increase the data accuracy of some critical questions, Epicollect5 provides the advanced option called "Double entry verification". The options is available as an advanced option for the following question types: * TEXT * NUMERIC * PHONE * TEXTBOX ![](https://3293478884-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F32OIF30CgrNUuRY6IjkW%2Fuploads%2Fgit-blob-f74aab12336a1421ee8f595cb39d86b7b49e961b%2Fdouble-entry-1.jpg?alt=media) When this option is enabled, the users will have to answer the same question twice and **both responses MUST match**. A common use case could be the user email address, social security number and so on. This validation is performed on the device directly therefore it will work both online and **offline** reducing the chances of collecting wrong data. {% hint style="warning" %} The comparison is case sensitive, i.e "John" and "john" do NOT match. {% endhint %} Let's see it in action: on the form below we enabled the option for a *"What is your email?"* question When the users answer this question they will have to enter the email address twice to proceed. ![](https://3293478884-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F32OIF30CgrNUuRY6IjkW%2Fuploads%2Fgit-blob-4c13b291c3b8c644abe9d15fb846373af36abbdc%2Fdouble-entry-2.jpg?alt=media) ### Web application | | | | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ### Mobile application | | | | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | | | | Have a look at the example project [**EC5 Double Entry Example.**](https://five.epicollect.net/project/ec5-double-entry-example)