[Nexus]

<form class="async">
    <input type="hidden" name="type" value="a"/>
    <input type="phone" data-type="phone" require/>
    <input type="email" data-type="email" require/>
</form>
<form class="async">
    <input type="hidden" name="type" value="b"/>
    <input type="phone" data-type="phone" require/>
    <input type="email" data-type="email" require/>
</form>
<form class="async">
    <input type="hidden" name="type" value="c"/>
    <input type="phone" data-type="phone" require/>
    <input type="email" data-type="email" require/>
</form>

<?php
	if(!isset($_POST['type']))
		exit('Bad request');
	
	$allowed_types=array('a','b','c');
	$type=preg_replace('#[^a-z]+?#uim',null,$_POST['type']);
	if(!in_array($type,$allowed_types))
		exit('Bad request');
		
	/*
		Какая форма получена - понятно, дальше нужно вызвать обработчик формы.
	*/