Adding a product to the cart does not necessarily mean a shopper is ready to buy. They may be comparing prices or postponing the decision. But if checkout is difficult or payments fail, the shop also loses customers who are ready to complete their purchase.
Start by checking the whole journey, from the cart to order creation and payment confirmation. This helps distinguish an interface problem from an integration fault or inaccurate analytics.
Compare the order system, payment provider and web analytics. If paid orders exist but purchase events are missing, fix measurement first. Otherwise, the team will change checkout based on an incomplete picture.
Distinguish an order being created, a payment attempt and a confirmed payment. For payment on delivery, use a status appropriate to your business: the absence of an online payment does not itself mean the customer abandoned the order.
Choose one reporting period and a sequence of stages: checkout started, delivery selected, payment initiated and order completed. If individual actions are not tracked, set up tracking or start with order data and a manual check.
The cart should show selected variants, quantities and product prices. Changing a quantity should recalculate the amount correctly; removing an item should not disrupt the remaining data.
Pay particular attention to costs that appear late: shipping, order processing and other compulsory charges. If the exact amount depends on the address, explain this early and show the calculation before the customer confirms the order.
Check discount codes. An error should explain what happened: the code has expired, does not apply to these products or requires a different order value. Customers should still be able to continue without the discount.
For ordinary retail purchases, consider checkout without mandatory account creation. If sign-in is necessary, for example for contractual B2B prices, explain why and provide a clear way to recover access.
For every required field, ask whether it is needed to process this particular order. A delivery address is unnecessary for a digital product without shipping, and company details are unnecessary for a standard consumer order unless the terms of that particular sale require them.
Baymard's research highlights how the number of fields and the effort involved in completing them affect checkout usability. Merely reducing the number of screens does not solve the problem if the remaining screen still requires too much work. Source: Baymard.
Check errors on a phone: are entered details preserved, is it clear which field needs correcting, and are addresses and telephone numbers from your target markets accepted? “Invalid details” without an explanation does not help someone complete an order.
Use addresses from your main service areas and products with different shipping requirements. Check that appropriate delivery methods and correct charges are available.
Review:
If the cart contains products with different dispatch times or shipping methods, explain whether the order will be split and how that affects the cost.
Go through a successful payment, a failed attempt and a return to the shop after cancellation. Use the payment provider's test environment; for checks in a live shop, agree on the handling of test orders beforehand.
After an unsuccessful attempt, customers should understand the order status and be able to retry or choose another payment method without completing all the fields again.
Returning to a “Thank you” page does not itself confirm payment. For example, Stripe recommends handling successful payments through server notifications: a customer may close the page after paying, so the browser-side process never finishes. Check the confirmation mechanism for whichever provider you use. Source: Stripe documentation.
Ask the developer to check that the order, payment and notifications are connected, repeated clicks do not create duplicates, and a “Payment processing” status is not presented as final success.
Hypothetical example: a customer orders two products on a phone and chooses delivery to a collection point.
Record each defect with the device, step, expected result and actual result. First fix errors that prevent order completion or distort amounts and statuses. Then address unclear terms and unnecessary actions.
If you cannot identify the cause yourself, a website audit can help establish the checks and prioritise improvements. Once checkout is fixed, you can move on to abandoned cart emails: they complement a working purchase journey but do not fix payment or delivery errors.
The outcome should be a specific list of obstacles, verified order scenarios and data you can use to assess subsequent changes.