Your checkout is broken: what to do in the first hour
When checkout breaks, the instinct is to start trying fixes. The faster path is almost always the boring one: confirm what is broken, find what changed, undo it, and only then work out why.
1. Confirm and scope it
Try a checkout yourself in a private browser window, as a guest, and note exactly where it stops. Then narrow it down: does it fail for every product or one? Every payment method or one? Every country or one? Desktop and mobile? The answer tells you whether this is an emergency for all customers or a problem for some of them.
If you have monitoring, the run evidence — the failing step, a screenshot, the console errors — usually answers these questions before you open a browser.
2. Find what changed
Checkouts rarely break on their own. Look at what happened in the hours before: a deploy, a plugin or module update, a settings change in the admin, a new promotion, a new marketing script, an expired API key or certificate at a payment or shipping provider.
Check the provider status pages too. If your payment gateway is having an outage, there is nothing to fix on your side — only something to communicate.
3. Roll back before you debug
If a change lines up with the start of the failure, undo it first and investigate later on staging. Disable the new plugin, revert the deploy, restore the setting. Every minute spent debugging on production is a minute of lost orders.
Then check again with a real checkout — not just by loading the page — and confirm orders are coming in.
4. Close the loop
Tell your team and, if customers were affected for long, consider a short message to those who abandoned their carts. Write down what broke, when it started, when it was noticed and when it was fixed. The gap between "started" and "noticed" is the thing to shrink next time. Related: WooCommerce checkout not working and Magento checkouts that break after a deploy.
Check your own store now, free: the WooCommerce checkout checker or the Magento checkout test walks the checkout in a real browser and shows the step where it stops.
Common questions
What should I do first when checkout breaks?
Confirm it yourself in a private window, note which steps, devices and payment methods fail, and tell support.
Should I debug or roll back?
Roll back the most recent change first if it is a likely cause; debug once customers can buy again.
How do I prevent it next time?
Test the checkout after every change and run a scheduled checkout check that alerts within minutes.