Your checkout is broken. Customers can't buy.
A broken Shopify checkout is the most expensive problem a store can have. Every hour it's down is direct, measurable revenue loss. We trace the fault and fix it — usually the same day.
- Root cause diagnosis — not just symptoms
- Checkout app and Functions isolation
- Shop Pay, shipping, and Markets checks
- Payment method re-validation
- Full end-to-end checkout test
- 30 days follow-up cover
No fix? You pay nothing.
The 6 most common checkout killers
Shopify checkout failures almost always come from one of these root causes. Knowing which one matters — the fix is completely different for each.
Checkout app conflict after an update
A shipping, upsell, or checkout-block app update introduced a conflict that breaks the complete-order step. One of the most common causes — and hard to see without isolating extensions and Functions.
Most common causeTheme additional scripts on checkout
Tracking pixels, chat widgets, or old checkout.liquid / additional-script leftovers can throw JavaScript errors on the hosted checkout. The cart looks fine; payment never starts.
Very commonCheckout Extensibility / Functions clash
Shopify's newer checkout UI extensions and Shopify Functions don't always play nicely with older apps. The result is a checkout that refuses to render rates, tips, or the pay button.
Common after Plus upgradesPayment method misconfiguration
Shopify Payments, Shop Pay, PayPal, or a third-party gateway is disabled, unverified, or using the wrong Markets currency. Checkout loads but hangs or errors at payment.
CommonDomain or SSL on the checkout host
A custom domain, expired SSL, or a bad redirect to checkout.shopify.com can block the page — especially on mobile. A domain connect or primary-domain change is often the trigger.
Less common but criticalShipping, Markets, or inventory block
Missing shipping rates, a Markets country rule, or an inventory reservation can stop customers completing checkout with no useful error. Logs and a test cart tell the story.
Often overlooked
How we fix it
We don't guess. We work through the Shopify checkout stack methodically until we find the exact fault — then we fix it at the root.
Tell us what's happening
Fill in a short form. Describe what the checkout does — or doesn't do. No technical knowledge needed. Screenshots help but aren't required.
⏱ 5 minutesWe trace the fault
We work through apps, checkout extensions, additional scripts, Shop Pay, shipping, Markets, and domain settings. We find the root cause — not just the first thing that looks wrong.
⏱ Same dayFixed and tested end-to-end
We fix the root cause and run a complete checkout test — product to payment confirmation. You get a written summary of what was wrong, what we changed, and how to prevent it.
⏱ Confirmed before we closeCheckout down after a checkout-app update
A UK homewares brand contacted us after the Pay now button stopped responding following a checkout upsell app update. The cart was fine. Checkout loaded. Nothing happened on tap. They'd already uninstalled two apps with no result.
The upsell app's checkout Function hadn't been updated for the latest checkout API. We disabled the broken extension, restored a working pay path, and confirmed a live test order before they re-enabled a compatible version.
"We thought it was Shopify itself. It was one checkout app. StoreFixHQ found it and we were taking orders again the same afternoon."
— Homewares retailer, UKWhat's covered — and what isn't
We're specialists in Shopify checkout failures. Here's exactly what falls within our scope.
We fix these Covered
- ✓ Checkout app, extension, and Functions conflicts
- ✓ Theme additional scripts breaking checkout
- ✓ Shop Pay and payment-method configuration
- ✓ Shipping rates, Markets, and inventory blocks
- ✓ Custom domain / SSL issues reaching checkout
- ✓ JavaScript errors on checkout.shopify.com
- ✓ Mobile-only checkout failures
- ✓ Cart emptying before payment
Outside our scope Not covered
- ✕ Shopify platform outages
- ✕ Payment processor outages (Shopify Payments / Stripe / PayPal infrastructure)
- ✕ Headless checkout with no documentation
- ✕ Checkout redesign or new feature development
- ✕ Issues requiring a full theme rebuild
Not sure if you're in scope? Send us a note — we'll tell you honestly before you pay anything.
No fix, no fee. Full stop.
If we can't restore your Shopify checkout, you pay nothing. We'll tell you exactly what we found and why it's outside our scope — so you know where to turn next.
- No payment taken upfront — invoiced only on successful fix
- Excludes issues outside the covered scope above
- 30 days follow-up cover included with every fix
- Same fault recurs within 30 days — we fix it again, free
Flat rates. No hourly surprises.
You know the cost before we start. All prices exclude VAT.
- Full diagnostic trace
- Root cause fix
- End-to-end checkout test
- Written handover summary
- 14 days follow-up cover
- Everything in Standard
- Same-day diagnosis & fix
- Priority queue — jump the line
- 30 days follow-up cover
- Prevention advice included
- Monthly checkout health check
- App update monitoring
- Pre-publish theme checks
- Priority response on any issue
- Unlimited fixes during plan