Your checkout belongs to Shopify. Atlas does not build it, style it or modify it. What Atlas does at checkout is apply the discounts your bundles and cart drawer produced, through Shopify's own discount system. This covers where to edit the checkout and what to be careful about if you are considering replacing it.
In this article:
Where to edit it
In your Shopify admin, go to Settings, then Checkout.
Configure customer accounts, contact method, address fields, tipping and marketing consent.
For the visual design, select Customize to open the checkout editor.
What you can change depends on your Shopify plan. Shopify Plus offers considerably more, including the ability to edit checkout with extensions and to customise the thank-you page.
What Atlas does at checkout
One thing: it applies discounts.
Bundle offers and cart drawer offers create Shopify automatic discounts. Shopify evaluates them during the cart and checkout and applies them, so the customer pays the right price without entering a code.
Atlas does | Atlas does not |
Apply bundle discounts | Style the checkout |
Apply cart drawer discounts | Add fields to the checkout |
Nothing else at checkout | Change the checkout flow |
Handle payments |
ℹ️ If a discount is missing at checkout, the cause is normally the discount configuration or the checkout path, not the checkout's design. See Why aren't my bundle discounts applying at checkout?
Customising with checkout extensions
Shopify checkout extensions let apps add content to the checkout. They are the supported way to customise it, and they coexist with Atlas without conflict, because Atlas is not present at the checkout beyond its discounts.
Replacing the checkout entirely
This is the decision that matters for Atlas.
⚠️ If you install a third-party checkout, a one-page checkout, or a cash on delivery app that bypasses the Shopify cart, Atlas discounts will not apply. Atlas applies discounts through Shopify Functions that run during the Shopify cart and checkout. A flow that skips them never triggers the discount, and there is no Atlas setting that changes it.
Cash on delivery causes a second, separate problem: those orders are excluded from Atlas revenue reporting, so they will not appear in your analytics either.
Before replacing your checkout, decide whether you are prepared to lose Atlas bundle and cart discounts on the orders that go through it. Showing customers an offer they will not receive is worse than not showing it.
What to check after any checkout change
Add a bundle offer to the cart on your storefront.
Go through to checkout.
Confirm the discount line appears with the right amount.
If you use a reward progress bar, cross the threshold and confirm the reward applies.
Complete a test order if you can.
💡 Test the checkout after any change to checkout settings, payment providers or apps that touch the cart. Discounts failing silently at checkout is the most expensive failure mode available, because every affected customer either pays more than promised or abandons.