title: How to create Stripe elements postal code that accepts UK postcodes?
body: <p>I'm creating a payment form with separate Stripe Elements:</p>
  
  <pre class="lang-js prettyprint-override"><code>var stripe = Stripe(...);
  var elements = stripe.elements();
  ...
  var postalCode = elements.create('postalCode');
  postalCode.mount('#postalCode');
  </code></pre>
  
  <p>This creates a field that accepts only digits. However, the UK's post codes contain letter as well. How do I allow these too? I want the user to be able to input pretty much any possible post code in the world.</p>