The following functionality prevents your customers from shipping to PO Box addresses.

Put this javascript in a custom header via the “add code to the header and footer” section in your store admin's Template Configuration Settings.

<script type="text/javascript">
 
var validatePO = function() {
	var addressString = $("#shipping_address1").val() + $("#shipping_address2").val();
	addressString = addressString.replace(/\./g,"");
	addressString = addressString.replace(/ /g,"");
	addressString = addressString.toLowerCase();
	if(addressString.indexOf('pobox') != -1) {
		alert("We can not ship to a PO Box shipping address. Please choose a different shipping address location.");
		return false;
	}
	else {
		return true;
	}
}
 
FC.client.on('customer-address-change', validatePO);
FC.client.on('checkout-submit', validatePO);
 
</script>