Short definition

Checkout — the process in an online store where a customer reviews and submits an order and the system records payment and order status.

Also known as: order flow.

The checkout starts when a customer begins completing an order and ends only when payment and order status have been processed reliably. The screen is one part of the process; inventory, email and back-office systems belong to the same workflow.

How does a checkout work?

The online store collects only the necessary data, calculates the total and creates a payment with the payment provider. The browser may return to a thank-you page, but the server should confirm the provider’s status through a verified webhook or, if needed, an API request. Reloading or double-clicking must not create a duplicate order.

What does this mean for a small business?

Every extra question or unexpected cost can make a customer abandon the checkout. Show shipping costs, VAT, the return policy, and payment options before the final step. Give customers a way to recover from errors and keep their cart for long enough. A short process helps, but not if it removes information people need before paying.

What should you check in a checkout?

  • show total price and delivery conditions before payment;
  • only ask for data that is necessary or legally required;
  • process each payment event only once, even when notifications are repeated;
  • test payment failures, cancellations, browser returns and duplicate webhook deliveries;

How it relates to other website choices

The payment provider processes the payment, while conversion only counts when the agreed order status is reached. Structured data on product pages must correctly reflect price and availability.