Google Chrome appears to proactively enforce client-side validation. Here is an example of what I’m seeing:

In this case, I have no client-side validation scripts (yet) although I have set the pattern attribute with a regular expression. Is there a way to instruct Chrome (and possibly other browsers) to NOT volunteer validation services?
pattern="(44)?0?[1-9](0[0-9]{8})"
You can use
novalidateattribute: http://www.w3schools.com/html5/att_form_novalidate.asp