Checkout Optimisation Starting at the Payment Layer

Much of what gets called checkout abandonment never was a design problem. Across the last three checkouts I took apart, between 9 and 17 percent of attempted payments failed at the processor and never returned — soft declines, 3-D Secure challenges dropped on mobile Safari, address verification mismatches on Canadian postal codes typed without the space. That is money standing at the till with a card out, and no button test recovers it. So this work starts at the payment layer and moves backwards into the cart. The payment layer, first: Decline codes come out of Stripe, Adyen or Shopify Payments and get split into declines the issuer made and declines you caused: retry logic firing instantly instead of on the intervals issuers tolerate, exemptions not requested where the transaction qualified, a wallet button rendering but failing on one OS version, card country against currency on your United States traffic. Then network tokenisation and account updater coverage on anything recurring, which on a pet autoship program is usually the largest single recoverable line and is almost never in a CRO backlog, because it lives in a tool the growth team does not open. The cost reveal, second: Abandonment concentrates at the moment total cost becomes known. For furniture that is freight and lead time; for cross-border Canadian carts it is duty and tax presentment. The work is deciding where that number appears and how early, then testing it rather than assuming earlier is always kinder. On one heavy-goods catalogue, moving freight onto the product page cut add-to-carts, raised checkout completion, and left revenue where it started — a result worth having precisely because it stopped a roadmap item. Threshold logic that actually moves order value is tied to the freight break, not to a round number somebody in marketing liked. The form, third: Address autocomplete tuned for Canadian formats including apartment lines and rural routes, validation firing on blur rather than on keystroke, express wallet position relative to the guest path, and account creation taken off the critical path entirely. Most of these are fixes rather than tests. They ship as a specified fix list with reasoning, and experiments are reserved for the choices where two reasonable people disagree. Instrumentation, without which none of the above is knowable: Distinct events for cart, contact, shipping, payment method selection, payment attempt, payment success and payment failure, split by wallet against card. Where those events do not exist, building them is the first deliverable and I will say so rather than infer a funnel from one begin_checkout event and a purchase. Out of scope: No processor migration. No rebuilding checkout on another platform. No checkout extensibility development on Shopify Plus — I write the specification, your developers or your agency build against it. No pricing or promotion strategy, no merchandising above the cart, and no subscription pricing design. Who I turn away: Stores under roughly 400 checkout starts a month. Every difference there is noise, and the honest advice is to fix the obvious defects and stop measuring. Teams whose checkout is locked by a platform they cannot modify and will not leave. And anyone whose brief is to bring the cart abandonment rate down as a number, because that rate falls whenever you make the cart harder to reach. I have watched a team celebrate a six-point improvement in it while revenue sat exactly where it had been for two quarters.