I am trying to make a zip code and postal code mandatory for shipping and billing information but i am not success kindly provide some solutions.
Multiselect Box called ‘Postal Code is Optional for the following countries’.
Select the countries you want the field as optional.
As far as concerned with code changes, It is always recommended to follow inbuilt features instead of code changes.
their will be a text box for the zip code their please add "required-entry" in the class attribute of the zipcode textbox.then it is done
<input type="text" title="<?php echo $this->__('Zip/Postal Code') ?>" name="billing[postcode]" id="billing:postcode" value="<?php echo $this->escapeHtml($this->getAddress()->getPostcode()) ?>" class="required-entry input-text validate-zip-international <?php echo $this->helper('customer/address')->getAttributeValidationClass('postcode') ?>" />
see i had added required-entry in class above