Things to take care when you opt for a single page checkout

• Data validation – Don’t wait until the user submits the form, validate and notify the user in real-time. Real-time inline validation will help your customers complete the checkout quickly with less effort and fewer errors. Make sure the notification is prominent enough that the user doesn’t skip it.

  
  

• Organize the checkout form – breakdown the checkout page into sections and keep the related items in close proximity.
  
  

• Avoid asking unnecessary information – Single page checkout is meant to be quick and easy. So, avoid asking unnecessary information.
  
  

Shipping and billing addresses will be the same for majority of the orders. Pre-fill the billing address details with shipping address instead of asking the user to do a redundant job.

Show the zip code field and hide city and state. When the user inputs the zip code, expand the form with pre-filled city and state fields. Ensure these fields are editable.

• Order summary in the right side area along with the call to action – pin this widget so that it follows the user when he scrolls down the checkout page.