UK Postcode & Address API for Developers

<!-- Add a div to house your 
     postcode input field -->
<div id="lookup_field"></div>

<!-- This is your existing form -->
<label>Address Line One</label>
<input id="first_line" type="text">

<label>Address Line Two</label>
<input id="second_line" type="text">

<label>Address Line Three</label>
<input id="third_line" type="text">

<label>Post Town</label>
<input id="post_town" type="text">

<label>Postcode</label>
<input id="postcode" type="text">

<script>
// Add this after your form
$.idealPostcodes.setup({
  // Add your API key
  api_key: 'ak_hk71kco54zGSgVf9ExxRVVNmolLNh',
  // Identify your fields with CSS selectors
  output_fields: {
    line_1: '#first_line',  
    line_2: '#second_line',         
    line_3: '#third_line',
    post_town: '#post_town',
    postcode: '#postcode'
  }
});

$('#lookup_field').setupPostcodeLookup();
</script>