Reviewed by Mayer Hyman, Payments Specialist | Reviewed for accuracy July 2026
Key Takeaways
- Fixing documented checkout friction can lift conversion rate by an average of 35.26% for large ecommerce sites, per Baymard Institute’s decade of checkout usability testing (Baymard Institute).
- Drop-off in a signup, payment, or upgrade flow isn’t a cart-abandonment problem specifically, it’s a funnel-wide friction problem that shows up anywhere a customer has to stop and act.
- A one-second delay in page load time can reduce conversions by roughly 7%, according to Akamai’s research on site performance (Akamai).
- Most drop-off in a purchase flow clusters at a handful of predictable moments: checkout, payment entry, and plan or subscription upgrades.
Why Checkout and Payment Flow Are Where Growth Is Won or Lost
Checkout and payment flow decide growth because that’s where intent either converts to revenue or gets lost to friction, and it’s a faster lever than any new feature or acquisition channel. Every eCommerce and SaaS team wants growth, but the handful of seconds between a customer deciding to buy and actually completing the transaction, checkout, payment entry, plan upgrades, is where the outcome actually gets decided.
The scale of the problem is well documented on the eCommerce side, but the same pattern shows up just as often in SaaS: a free-trial user hits the upgrade screen and stalls, or a signup form asks for a card before the customer has seen enough value to justify entering one. Some drop-off is unavoidable, comparison shoppers, budget approvals, saved-for-later decisions, but a meaningful share is self-inflicted: slow pages, too many form fields, unexpected costs revealed at the last step, or a payment flow that feels bolted onto the product rather than part of it.
Where the Drop-Off Actually Happens
Most purchase flows lose customers at the same few points, regardless of industry:
- Checkout: extra steps, redirects to a third-party payment page, or surprise fees at the final screen.
- Payment entry: forms that ask for more information than the transaction requires, or that don’t support the payment method a customer expects.
- Upgrades: moving from a free plan or trial to paid, where friction reads as risk rather than progress.
These aren’t cosmetic issues. Baymard Institute’s checkout usability research, built on years of testing large ecommerce sites, found that fixing documented friction points in the checkout flow could lift conversion by an average of 35.26% (Baymard Institute). That’s a substantial swing driven almost entirely by removing steps, not by adding features.
Page Speed Is Part of the Payment Experience
Conversion isn’t only about how many fields a checkout form has. Speed compounds every other decision made in the flow. Akamai’s widely cited research on retail site performance found that a one-second delay in page load time can reduce conversions by around 7% (Akamai). A payment form that takes an extra second to render, or that redirects to a separate domain to process a card, introduces exactly the kind of delay that research keeps flagging as a conversion killer.
This is why “optimizing the payment flow” and “improving page speed” tend to be the same conversation in practice. A checkout page that calls out to a slow, disconnected payment gateway inherits that gateway’s latency, and the customer doesn’t distinguish between a slow site and a slow processor. They just leave.
What “Seamless” Actually Means in a Checkout or Upgrade Flow
The businesses that consistently improve purchase completion tend to focus on the same few things, not more features, but less resistance between intent and completion:
Embedded, Not Redirected, Checkout
When payment fields live directly inside the product or storefront, rather than sending the customer to a separate hosted page, there’s one less context switch and one less place for the customer to reconsider. Embedded checkout also keeps branding and layout consistent, which matters more for trust than most teams assume.
Fewer Steps Between Decision and Done
Every additional form field, confirmation screen, or account-creation prompt is a chance for a customer to stop. Baymard’s testing consistently shows that the shortest viable checkout, one that only asks for what the transaction actually requires, outperforms longer flows even when the longer flow offers more reassurance along the way.
Payment That Feels Like Part of the Product
Upgrade flows are a particularly common failure point. A customer moving from a free trial to a paid plan is already primed to buy; a payment step that looks and feels disconnected from the rest of the product reintroduces doubt at exactly the wrong moment.
Where a Payments Partner Fits Into This
None of this is really about picking a payment gateway in isolation. It’s about whether the checkout, the fraud checks, and the chargeback handling behind it can move at the same speed as the rest of the product. Cartis Payments is a payment processing provider built for merchants, ISVs, and B2B platforms that need exactly that: card processing, fraud protection, and chargeback management delivered through a single API rather than a patchwork of vendors, so the checkout experience doesn’t inherit someone else’s latency or someone else’s UI.
For teams evaluating their own conversion funnel, the practical starting point is usually a short audit: where in the flow do customers actually stop, and is that a product problem or a payments infrastructure problem. Those are two different fixes, and conflating them is why some checkout redesigns don’t move the needle.
Frequently Asked Questions
Is checkout drop-off different from a SaaS upgrade-flow drop-off?
The root causes overlap, form friction, unclear pricing, a disconnected payment step, but the fix differs. eCommerce checkout optimization is about the path from cart to confirmation; a SaaS upgrade flow is about the path from trial to paid plan, where the customer is often mid-product rather than mid-purchase. Both benefit from removing unnecessary steps and keeping payment embedded in the existing experience.
How much does page speed actually affect checkout conversion?
Research from Akamai found that a one-second delay in page load can reduce conversions by roughly 7%. In a payment flow, that delay is often caused by redirects to a separate, slower payment gateway rather than the storefront itself.
Does embedded checkout really convert better than a redirect to a hosted payment page?
Directionally, yes. Fewer context switches and fewer form fields consistently outperform longer, multi-page flows in Baymard’s checkout usability testing, and embedded flows remove the redirect step entirely.
What should we look at first if our upgrade or checkout flow is underperforming?
Map where customers actually stop, checkout, payment entry, or upgrade, and separate product friction (too many fields, unclear pricing) from payments infrastructure issues (slow gateway, disconnected fraud checks, unsupported payment methods). Contact Cartis if the second category turns out to be the bottleneck.
