> 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
The options is available as an advanced option for the following question types:
* TEXT
* NUMERIC
* PHONE
* TEXTBOX
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.
### Web application
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### Mobile application
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Have a look at the example project [**EC5 Double Entry Example.**](https://five.epicollect.net/project/ec5-double-entry-example)