The checkout page is the last page a user visits before finally decide to complete a purchase on your website. It’s where window shoppers turn into paying customers. If you want to leave a good impression, you should provide optimal usability of the billing form and improve it wherever it is possible to.
In less than one day, you can add some simple and useful features to your project to make your billing form user-friendly and easy to fill in. A demo with all the functions covered below is available. You can find its code in the GitHub repository.
Source: Smashing Magazine Improve Your Billing Form’s UX In One Day