Is it possible to require 2 input fields be the same before a form can be submitted?

We ask for our customers to enter and then re-enter their account number.  Sometimes these fields don't match and we aren't sure which number is accurate.

You can use conditional logic to compare entered numbers and to hide submit button if the entered values are not the same. You can also show additional text field as warning message to your users.

I have made a sample form and set contrition inside of it, like this. 

Here is my sample form: https://form.jotform.com/61086270421953 

Feel free to test it and clone it. 

Hope this will help. Let us know if you need further assistance.