// Hide standard shipping option when free shipping is available
add_filter( 'woocommerce_available_shipping_methods', 'hide_standard_shipping_when_free_is_available' , 10, 1 );
/**
* Hide Standard Shipping option when free shipping is available
*
* @param array $available_methods
*/
function hide_standard_shipping_when_free_is_available( $available_methods ) {
if( isset( $available_methods['free_shipping'] ) AND isset( $available_methods['flat_rate'] ) ) {
// remove standard shipping option
unset( $available_methods['flat_rate'] );
}
return $available_methods;
}add this to your themes functions.php file.