Overview
If you run a Basic, Shopify, or Advanced (non-Plus) store, you have a hard cutoff coming: August 26, 2026 is the deadline for stores on a non-Plus Shopify subscription plan to upgrade their existing Thank you and Order status pages to the new version of those pages. After that date, Shopify auto-upgrades your store, strips legacy customizations, and any tracking, COD fields, or thank-you page upsells still wired to the old system go silent. This guide walks you through what breaks, how to audit your store, and the exact migration path to Checkout UI Extensions, Web Pixels, and Shopify Functions before the cutoff.
Contents
What actually changes on August 26, 2026
Shopify has been retiring its legacy checkout system in phases. The core checkout pages already moved years ago: the main checkout pages (Information, Shipping, Payment) moved off checkout.liquid back in August 2024. Plus stores hit their Thank You and Order Status deadline on August 28, 2025. Non-Plus stores are next.
On the cutoff date, Shopify will auto-upgrade all non-Plus stores. Any custom code in checkout.liquid, any additional scripts on thank-you and order status pages, and any apps that injected into the legacy checkout will stop working. There is no opt-out. If you don't upgrade your pages again before August 26, 2026, then your Thank you and Order status pages will be auto-upgraded to the new pages, and Shopify's own help center confirms the legacy customizations are not preserved.
The replacement framework is Checkout Extensibility. Shopify checkout extensibility is a new checkout framework that replaces checkout.liquid, additional scripts, and Shopify Scripts with secure, sandboxed tools: checkout UI extensions, Shopify Functions, and Shopify Pixels. It is now the only supported way to customize checkout going forward.
Side note - There is a related but separate deadline you should know about. Shopify Scripts stops working June 30, 2026. The full Shopify checkout extensibility upgrade auto-applies to every non-Plus store on August 26, 2026. If you use Scripts for discount or shipping logic, that migration is even more urgent.
What breaks if you do nothing
The painful part of this transition is that nothing visibly crashes. Orders keep going through. But the systems downstream of checkout - your ad platforms, your COD process, your post-purchase upsells - quietly stop working.
Here is what to expect if you let the auto-upgrade run without preparation:
Google Ads and Meta pixel conversions: Google Ads campaigns will stop reporting conversions. ROAS numbers will drop to zero overnight. Smart Bidding then optimizes against zero-value conversions, which usually means you pause campaigns and lose a week or more of revenue before diagnosing it.
COD custom fields and phone verification: Many COD merchants added custom phone fields, delivery note inputs, or alternative address fields through checkout.liquid or third-party apps that inject into the checkout. All of that needs to move to Checkout UI Extensions.
Thank-you page upsells and content: Any script-injected upsell, review prompt, or referral widget on the Thank You or Order Status page stops rendering.
Affiliate tracking and tag managers: Affiliate scripts, GTM containers, and custom analytics pasted into Additional Scripts go dark on the cutoff date.
Missing these deadlines will result in an automatic upgrade by Shopify and the removal of all existing checkout.liquid and Additional Scripts customizations. You won't be able to use unsupported scripts or apps anymore, and your checkout experience will revert to a default setup.
Step 1 - Audit your current checkout customizations
Before you migrate anything, you need a complete inventory of what is running today. Without it, you will miss tracking pixels and find out three weeks after auto-upgrade that your Meta CAPI events stopped firing.
From your Shopify admin, go to Settings > Checkout.
Look for the upgrade banner. In the Configurations section, on the configuration that you want to update, click Upgrade Thank you and Order status pages by August 26, 2026 to expand the notice. Click Review customizations.
Open the Additional Scripts field and copy every line into a document. Note what each script is for: Google Ads, Meta Pixel, TikTok, affiliate, custom JavaScript, etc.
Open the Order Status page additional scripts section and do the same.
List every app that touches checkout, the Thank You page, or the Order Status page. Flag any that have not been updated for Checkout Extensibility.
If you are on Shopify Plus or have ever requested checkout.liquid access, document every customization in that file too.
Tip - Take screenshots of the rendered Thank You and Order Status pages on desktop and mobile. After migration, you will use these as a visual diff to confirm nothing is missing.
What if I don't see a banner in Settings > Checkout?
You can still be at risk. Even if you don't see a banner, check your Additional Scripts box. If there's any JavaScript in there, it needs to move to Customer Events before August 26. Some stores also have scripts injected via apps that won't show up in the upgrade report - check the app list manually.
Step 2 - Migrate tracking pixels to Web Pixels
For most non-Plus merchants, tracking is the single most impactful migration. Web Pixels are Shopify's replacement for raw JavaScript in Additional Scripts. Web Pixels are Shopify's purpose-built replacement. They run in an isolated sandbox, access a standardized set of customer event data (page views, cart events, checkout steps, purchases), and comply fully with PCI DSS v4 requirements.
Go to Settings > Customer events in your Shopify admin.
For Google, Meta, TikTok, and Pinterest, install Shopify's official channel app rather than pasting tags manually. Use Shopify's native integrations for Meta, Google, TikTok, and Pinterest - these are now pre-built and launch directly from your admin without developer involvement.
For anything else (custom analytics, niche affiliate networks), click Add custom pixel and paste your tag inside the sandboxed pixel template. Subscribe to the standard events you need:
page_viewed,product_viewed,checkout_started,checkout_completed,payment_info_submitted.Map your revenue and currency fields explicitly. Verify the purchase event fires with the correct transaction value. One merchant in the Shopify Community forums migrated their Google tag but forgot to map the revenue field - they ran campaigns for three weeks with conversions reporting at $0 value, which destroyed their Smart Bidding performance.
Set each pixel's permission to "Not required" or "Required" based on your consent strategy and connect it to your Customer Privacy API setup.
Tip - After you publish a pixel, place a real test order and verify the conversion lands in Google Ads, Meta Events Manager, and any other destination within 24 hours. Don't trust the preview - test the real funnel.
Step 3 - Rebuild Thank You and Order Status pages with app blocks
The new Thank You and Order Status pages are built in the checkout and accounts editor using blocks instead of Liquid templates. Shopify's upgrade report will tell you which of your existing apps are already compatible.
On the Upgrade guide page, go to the Apps section. In the Tracking and analytics section click Manage next to an app to set up app pixel tracking to work on the new Thank you and Order status page.
In the Page customizations section, click Add blocks to recreate your page customizations using blocks.
For each old script-injected feature, find a Checkout Extensibility-ready replacement in the Shopify App Store. Upsells, review prompts, referral programs, and loyalty widgets all have post-purchase extension versions.
Use the editor to position blocks: order summary, custom message, upsell offer, social proof, feedback prompt.
Save the configuration as a draft until you have tested it end-to-end.
What if my app isn't Checkout Extensibility compatible?
Contact the developer first; most have shipped updates by now. If an app only uses script tags/Additional Scripts on Thank You/Order Status, find a replacement that supports Checkout Extensibility. If no replacement exists, build a lightweight custom UI extension - they are React-based components built through the Shopify CLI.
Step 4 - Move checkout logic to Shopify Functions and UI Extensions
If your store does anything beyond pixels and content - conditional payment methods, surcharges, custom fields, hidden shipping methods - that logic also needs to move.
Discounts, shipping rules, payment customizations: these go to Shopify Functions. Shopify Functions is the direct replacement. Functions run in a WebAssembly sandbox and cover the same use cases - custom discounts, shipping rates, cart transformation - using JavaScript or Rust instead of Ruby. They're deployed as apps rather than scripts entered in the admin.
Custom fields and UI changes: these go to Checkout UI Extensions. Examples include delivery instructions, phone verification, gift messages, tax ID fields, and B2B PO numbers.
If you don't have a developer, search the Shopify App Store for an app that already does what you need. Many merchants can replace custom logic with off-the-shelf apps built on Functions and UI Extensions.
For COD-specific flows, prioritize a Checkout UI Extension that captures phone, alternate address, and delivery notes, plus a Function that hides COD as a payment method when conditions aren't met (e.g., cart value, postal code).
Side note - If you're still on Shopify Scripts (Plus only historically, but worth noting), remember that if your store uses Scripts for discount combinations, tiered shipping, B2B pricing, or bundle logic - that logic stops working entirely on July 1, 2026. Plan that migration first if it applies to you.
Step 5 - Test, publish, and monitor
This is the step most merchants under-invest in, and it's where silent revenue loss starts.
Place real test orders through every checkout path: desktop, mobile, guest, logged-in, COD, prepaid, discounted, subscription, and any third-party payment method you support.
For each test order, verify: the order appears correctly in admin with custom field data attached, the Thank You page renders all blocks, and the conversion fires in every connected ad platform with the correct value and currency.
Compare a week of conversion data in Google Ads and Meta against actual orders in Shopify. The numbers should match within typical attribution variance.
Publish your new configuration in Settings > Checkout.
Keep your old configuration as a fallback. If you need to revert to the previous version of your Thank you and Order status pages, then you can revert before August 26, 2026. You can revert to the old versions of your Thank you and Order status pages if your store meets all of the following conditions: Your store was created before January 6, 2025. Your store has pre-existing customizations to your Thank you and Order status pages using additional scripts or apps that use script tags. You manually upgraded your Thank you and Order status pages less than 30 days ago.
Monitor your ad platform dashboards daily for the first two weeks after publishing.
Tip - Don't wait until July or August. For non-Plus merchants, do not push this migration past Q2 2026. Agency capacity tightens quickly as the deadline approaches.
FAQ
What exactly happens on August 26, 2026?
August 26, 2026. On that date, Shopify will auto-upgrade all non-Plus stores and remove all legacy checkout customizations, additional scripts, and checkout.liquid code. Your checkout reverts to the default Checkout Extensibility experience with whatever Extensibility-compatible apps you have installed.
Does this apply to Basic, Shopify, and Advanced plans?
Yes. The deadline applies to every non-Plus subscription. This guide is for merchants with stores that are on a non-Plus Shopify subscription plan. Stores on the Pause and Build plan are upgraded automatically. Stores on the Shopify Plus plan need to follow the Shopify Plus upgrade guide instead.
How do I know if my store was already auto-upgraded?
Go to Settings > Checkout and check the Configurations section. If you see no upgrade notice and your Additional Scripts field is empty or locked, you are likely on the new system. If you still see the "Upgrade Thank you and Order status pages by August 26, 2026" notice, you have not been upgraded yet.
I don't use Shopify Scripts. Do I still need to migrate?
Almost certainly yes. Even if you have never touched Scripts (which were largely a Plus feature anyway), you probably have Google Ads, Meta, or analytics tags in the Additional Scripts box. Those still need to move to Web Pixels before August 26.
Can I revert if the new pages break something?
Only within a 30-day window after a manual upgrade, and only if your store meets Shopify's eligibility conditions for reverting. After August 26, 2026, the legacy system is gone for good - reverting is no longer possible.
How long does a typical non-Plus migration take?
For a store with standard pixels and one or two checkout apps, plan on a few hours to a couple of days, mostly spent testing. For stores with custom COD flows, conditional payment methods, or multi-pixel setups, budget two to four weeks including testing and a monitoring window.
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