Checkout optimisation is the work of making it easier for someone who has decided to buy to finish paying. It covers the basket, delivery and payment steps, and removes the surprises, effort and doubts that make shoppers give up between pressing the checkout button and seeing the order confirmation.
How checkout optimisation works
It starts with measurement. GA4 ecommerce tracking records begin_checkout, add_shipping_info, add_payment_info and purchase, so you can see how many shoppers reach each step and where they leave. Your checkout abandonment rate is the headline figure; the step-by-step view tells you where to look.
Then you find the cause at the step that loses most people. The usual culprits fall into a few groups:
- Cost surprises: delivery charges, service fees or minimum order rules that appear late.
- Effort: forced account creation, long forms, a postcode lookup that fails, or a phone field that rejects a valid UK number because it contains a space.
- Doubt: no clear returns policy, no delivery date, or a payment page that looks unfamiliar.
- Payment trouble: missing payment methods, or a card verification step that fails or times out.
- Technical faults: errors on certain browsers, slow scripts, or discount code boxes that break.
Session recordings and form analytics show where individual shoppers struggled. Fixes are then made one at a time and checked against the step figures.
Why it matters
A shopper in checkout has already done the hard part: found you, chosen a product and decided to buy. Losing them there wastes the marketing spend that brought them. Raising the share who finish usually brings in more revenue from traffic you already pay for, which is cheaper than buying more visits.
UK rules shape the checkout as well. Consumers should see VAT-inclusive prices in pounds. Under the DMCC Act 2024, drip pricing, where unavoidable fees are added late in the purchase, is a banned practice, so any mandatory charge must be in the headline price from the start. Delivery costs should also be clear before the shopper commits.
Many online card payments in the UK trigger Strong Customer Authentication, usually through 3-D Secure, where the bank asks the shopper to approve the payment in their banking app. A good checkout handles that step cleanly, including when the shopper switches to the app and comes back.
Common mistakes
- Forcing registration before payment. Offer guest checkout and invite account creation after the order is placed.
- Revealing delivery costs at the last step. It is one of the most common reasons a near-certain sale falls away.
- Asking for data you do not need, such as a date of birth or a second phone number.
- Changing everything at once, so nobody can tell which change helped and which hurt.
- Testing only on a desktop, when many shoppers pay on a phone using autofill or a wallet such as Apple Pay or Google Pay.
- A prominent promo code box that sends shoppers off to search for codes, some of whom never return.
How to act on it
Place a real order on your shop from a phone, as a new customer, using a UK address with an awkward format such as a flat number or a house name. Note every moment of hesitation. Then build a funnel exploration in GA4 from begin_checkout to purchase and find the step with the largest drop.
Fix the cheap, certain problems first: show delivery costs on product pages, allow guest checkout, add the wallet payments your platform supports, and make error messages say exactly what to correct. Test the less certain ideas one at a time. On Shopify and other hosted platforms parts of the checkout are locked, so some improvements have to happen in the basket or on the product page instead.
When the checkout is part of a larger rebuild, I treat it as one of the protected journeys in a website redesign, measured before and after launch so any drop is caught quickly.