You could use JavaScript/jQuery to fetch those values from the input fields and write them to your review area.
I did this in the past, for a custom one page checkout, so it may require some tweaking for your needs. You just need to make this an onClick event on the continue button, if I remember what I did correctly.
function saveShipping(){
if($("billing:use_for_shipping_no").checked) {
var shippingStreet1 = $("shipping:street1").value;
var shippingStreet2 = $("shipping:street2").value;
var shippingCity = $("shipping:city").value;
var shippingPostalCode = $("shipping:postcode").value;
//lumping it into one variable for output
shippingData = $('shipping:firstname').value+' '+$('shipping:lastname').value+'<br/>'+shippingStreet1+'<br/>';
if(shippingStreet2 != "") {
shippingData += shippingStreet2+'<br/>';
}
shippingData += shippingCity+', '+$("shipping:region_id").options[$("shipping:region_id").selectedIndex].innerHTML+', '+$('shipping:country_id').value+', '+shippingPostalCode
//all data
jQuery("#shipping_data").html(shippingData);
//just the postal code
jQuery("#shipping_post_code_html_element").html(shippingPostalCode);
}
else{
//new variable
var billingPostalCode = $('billing:postcode').value;
billingData = $('billing:firstname').value+' '+$('billing:lastname').value+'<br/>'+$('billing:street1').value+'<br/>'
if($('billing:street2').value != '') {
billingData += $('billing:street2').value+'<br/>';
}
billingData +=$('billing:city').value+', '+$("billing:region_id").options[$("billing:region_id").selectedIndex].innerHTML+', '+$('billing:country_id').value+', '+$('billing:postcode').value
//all billing data
jQuery("#shipping_data").html(billingData);
//just the postal code
jQuery("#shipping_post_code_html_element").html(billingPostalCode);
}
}
Update
If you just want the postal code, the code above stores it in the variable shippingPostalCode, if they opted to use a separate shipping address, and just plucks the value from the input field if they use the same billing/shipping info. You can send just the postal code to be written the same way, like so:
function saveShipping(){
if($("billing:use_for_shipping_no").checked) {
...
//all data
jQuery("#shipping_data").html(shippingData);
//just the postal code
jQuery("#shipping_post_code_html_element").html(shippingPostalCode);
}
Just replace "shipping_post_code_html_element" with the id of the html element you're wanting to write it to.
Similarly, for the else statement (where I'm using the billing data in the case that shipping/billing are the same), I'd put the billing zip code in a variable, just to make the code look nicer, and change it to something like this:
else{
//new variable
var billingPostalCode = $('billing:postcode').value;
...
//all billing data
jQuery("#shipping_data").html(billingData);
//just the postal code
jQuery("#shipping_post_code_html_element").html(billingPostalCode);
}
I updated the code above, too, so you can just pick out the pieces you don't need.
Best Answer
You can change that in admin panel, itself.
Navigate to
You can select the countries for Zip/Postal Code optional.