CartDNA published a checkout abandonment study on August 17, 2026 that puts a hard number on something most CRO teams already suspected: mobile checkout is where conversion goes to die. Across sites audited in the US, UK and Europe, mobile usability problems showed up in nearly two out of every three checkouts. Here is what the research actually measured, the six friction categories behind it, and what to fix first if your own checkout hasn't had a real audit in a while.
CartDNA's August 2026 research found mobile usability issues in 63.2 percent of checkouts audited across the US, UK and Europe, with mobile shoppers hitting 13 percent more friction than desktop shoppers on the same sites. Checkout complexity affected 23.46 percent of sites and weak trust signals affected 19 percent. Cutting form fields and adding trust signals near the payment step are the fastest fixes available.
What did the CartDNA research actually measure?
CartDNA audited live ecommerce checkout flows across three markets, the US, the UK and Europe, scoring each one across six friction categories: payment availability, mobile usability, checkout complexity, commercial transparency, trust signals, and international localisation. Mobile usability came out as the most widespread problem by a wide margin, present in 63.2 percent of the checkouts examined. On the same sites, mobile shoppers experienced 13 percent more friction overall than desktop shoppers, meaning the same checkout that works acceptably on a laptop is measurably worse for the majority of visitors who arrive on a phone.
| Friction category | Share of checkouts affected | What it typically looks like |
|---|---|---|
| Mobile usability | 63.2% | Small tap targets, thumb reach issues, broken autofill |
| Checkout complexity | 23.46% | Unnecessary steps, redundant form fields |
| Trust and reassurance signals | 19% | Missing security badges, no visible return policy near payment |
| Commercial transparency | Not itemized in headline figures | Late disclosure of shipping cost and delivery timing |
Why does mobile keep losing to desktop on the same checkout?
The gap is structural, not incidental. Most checkout flows still get designed and QA'd on desktop first, then squeezed onto a smaller screen afterward, rather than built mobile-first from the start. That produces exactly the pattern CartDNA measured: forms that were tolerable across a full-width desktop layout become a scroll-heavy, fiddly sequence on mobile, autofill fields that worked in testing on one browser fail silently on another, and buttons sized for a mouse cursor sit too close together for a thumb. Mobile visitors already convert at roughly half the rate of desktop visitors industry-wide, and they represent the majority of ecommerce traffic, which is exactly why this single category deserves first attention in any 2026 checkout audit.
Run your own checkout on a real phone, not a resized browser window, end to end, including a wrong password, a declined card and a promo code that does not apply. Most of the friction CartDNA measured only shows up when you actually try to break the flow rather than click through the happy path.
What does checkout complexity actually cost you?
Complexity showed up in 23.46 percent of the checkouts CartDNA examined, which lines up with separate research showing 62 percent of mobile form abandonments cite complexity as the direct cause. Every field you ask for that isn't strictly necessary is a decision point where a mobile visitor on a spotty connection, in a hurry, or simply annoyed, leaves. Fields most commonly worth cutting: a separate billing address field when it matches shipping by default, a phone number field marked required when it isn't used for anything critical, and account creation forced before purchase rather than offered as an option after.
Why do trust signals matter enough to measure separately?
Trust and reassurance signals were weak or absent in 19 percent of the checkouts audited, and separate research puts a number on what that costs: sites that display trust signals, security badges, a visible return policy, real support contact, inline with the payment fields see roughly 18 percent higher payment completion rates than sites without them. The placement matters as much as the presence. A trust badge in the footer does little; the same badge sitting next to the card number field, at the exact moment someone is deciding whether to hand over payment details, does real work.
Move your security badge, return policy link and a real support contact to sit directly beside the payment form, not the page footer. It is a ten-minute layout change with one of the better cost-to-impact ratios available in conversion optimization work.
What should you fix first if you haven't audited your checkout recently?
- Test the full checkout on an actual mobile device, not a browser resize, including error states and edge cases like a declined card.
- Count your form fields and cut anything not strictly required to complete the purchase; aim to justify every field you keep.
- Move trust signals, security badges, return policy, support contact, next to the payment fields rather than in the footer or a separate page.
- Disclose shipping cost and delivery timing before the final payment step, not as a surprise on the last screen.
- Check autofill and autocomplete actually populate correctly on both iOS and Android; broken autofill is invisible in desktop QA and common on mobile.
This is the same territory Baymard's 2026 checkout audit covered from a different angle, finding that a majority of sites still fail basic checkout UX standards. Two independent studies landing on the same conclusion within weeks of each other is a strong signal that this is not a one-off methodology quirk. It is a real, widespread gap.
Frequently asked questions
What did CartDNA's 2026 checkout research find?
Published August 17, 2026, CartDNA's research across the US, UK and Europe found mobile usability issues in 63.2 percent of checkouts audited, with mobile shoppers experiencing 13 percent more friction than desktop shoppers on the same sites. Checkout complexity affected 23.46 percent of checkouts and weak trust signals affected 19 percent.
Why is mobile checkout friction such a common problem?
Most checkout flows were designed and tested on desktop first, then adapted for mobile, rather than built mobile-first. That leaves mobile-specific problems unaddressed: thumb reach zones, small tap targets, autofill and autocomplete failures, and multi-step forms that were fine on a large screen but painful on a small one.
What are the six friction categories in the CartDNA research?
Payment availability, mobile usability, checkout complexity, commercial transparency, trust signals, and international localisation. Mobile usability was the most widespread issue at 63.2 percent of checkouts, followed by checkout complexity at 23.46 percent and weak trust signals at 19 percent.
Do trust signals actually affect checkout conversion?
Yes. Sites that display trust signals, security badges, clear return policy, real support contact, inline with the payment fields see roughly 18 percent higher payment completion rates than sites without them. Trust signals matter most at the exact moment someone is about to enter card details, not earlier in the funnel.
What is the fastest fix for mobile checkout friction?
Cut form fields first. 62 percent of mobile form abandonments cite complexity as the cause, and it is usually the cheapest fix available: remove fields you don't strictly need, enable autofill correctly, and move to single-page checkout where your platform supports it before investing in bigger structural changes.
The takeaway
Nearly two-thirds of checkouts have a measurable mobile usability problem, and the fixes are not expensive R&D projects. Cut unnecessary form fields, move trust signals next to the payment form instead of the footer, disclose shipping costs before the final step, and actually test the flow on a real phone. CartDNA's numbers say most sites still haven't done the basics; doing them is still one of the highest-leverage moves available in ecommerce right now.
Sources & further reading
- Newsfile: CartDNA Research Identifies Mobile Friction and Payment Gaps (August 2026)
- Yahoo Finance: CartDNA Research Identifies Mobile Friction and Payment Gaps
- Digital Applied: Ecommerce Checkout Optimization: UX Guide 2026
- Digital Applied: Conversion Rate Benchmarks 2026: Industry and Channel Data