Quick Answer

August 28, 2025 is the deadline for Shopify Plus merchants to upgrade their Thank You and Order Status pages off checkout.liquid, additional scripts, and script-tag apps onto Checkout Extensibility. After this date, those fields become view-only, personally identifiable information stops being passed to legacy tracking scripts, and any app still relying on script tags stops working. Stores that miss the deadline are not immediately broken, but tracking accuracy degrades and the store becomes locked out of further customization until migration is complete. Automatic upgrades that strip all legacy customizations begin in January 2026.

Published August 11, 2025 by Alex Rivera, Senior eCommerce Developer at NCM Technology — 8 min read

Introduction

The Shopify Plus checkout upgrade deadline for Thank You and Order Status pages lands on August 28, 2025 — just over two weeks from when this is being published. If your store still has Additional Scripts, checkout.liquid customizations, or apps using script tags on these two pages, this deadline affects you directly, whether or not you have been actively tracking Shopify’s checkout migration timeline.

We covered the broader move to Checkout Extensibility in our Shopify Plus checkout customization guide when the main checkout pages migrated back in August 2024. This deadline is the second and more consequential phase — specifically targeting the post-purchase pages where most merchants run their conversion tracking, loyalty integrations, and post-purchase upsells.

 

 

What Actually Happens on August 28, 2025

Shopify’s own Plus upgrade guide is direct about the consequences. Once the deadline passes without migration, the Additional Scripts section in Checkout settings becomes view-only — you can see what is there, but you cannot edit it. Any app still using script tags on the Thank You or Order Status pages stops working entirely. And critically, personally identifiable information — email and phone number specifically — is no longer passed through additional scripts, checkout.liquid, or the checkout_completed pixel event on these legacy pages.

That last point is the one most merchants underestimate going into this deadline. Your tracking pixels do not stop firing — they keep firing on schedule. What changes is that the data they receive is stripped of the customer-identifying information that ad platforms need to attribute a conversion to a specific user. The order still completes successfully. The conversion simply becomes invisible to your ad platforms, which typically shows up as a sudden, unexplained drop in reported return on ad spend with no corresponding change in actual sales.

Who This Deadline Applies To

This deadline is specific to Shopify Plus merchants. Non-Plus stores — Basic, Shopify, and Advanced plans — have a separate, later deadline of August 26, 2026 for this same migration. If you are unsure which deadline applies to your store, check Settings → Checkout in your Shopify admin. If you see a banner referencing an upgrade deadline, your store has customizations on these pages that require action.

 

 

How to Check If You Are Affected

From Shopify Admin, go to Settings → Checkout. In the Configurations section, look for a notice referencing the upgrade deadline. Clicking it opens your personalized upgrade report, which Shopify’s own Plus upgrade guide describes as showing every active customization, the source it comes from, and a suggested approach for recreating it under the new system. This report is the single most useful starting point — it tells you exactly what you have to migrate rather than requiring you to audit your scripts manually.

If your upgrade guide comes back empty, you can skip directly to publishing the new versions of these pages, since you have no legacy customizations at risk.

Red Flags Worth Walking Away From

• Tracking and analytics scripts — Google Tag Manager, Meta Pixel, TikTok Pixel, and similar tracking code running through Additional Scripts needs to move to Shopify’s Custom Pixels under Customer Events, not Additional Scripts
• Apps using script tags — check with each app vendor on whether they have shipped a Checkout Extensibility-compatible version. Apps that have not updated will simply stop functioning on these pages
• Custom checkout.liquid code — any custom HTML, CSS, or JavaScript directly in checkout.liquid for these pages needs to be rebuilt as a Checkout UI Extension or post-purchase extension
• Custom fields for gift messages or special instructions — if these were implemented through checkout.liquid, they need to be rebuilt as Checkout UI Extensions, which can now include validated fields and conditional logic that the old system could not support
• Post-purchase upsells and surveys — any interactive content added through JavaScript on the Thank You page needs to migrate to dedicated post-purchase extensions

If You Miss the Deadline

Missing August 28, 2025 does not mean your store stops processing orders. It means your legacy customizations on these two pages become locked — visible but uneditable — and tracking accuracy degrades due to the PII restriction. Automatic upgrades that strip all legacy customizations entirely begin in January 2026, at which point the migration is no longer optional and happens without further notice from Shopify.

If you are reading this after the deadline has already passed for your store, the path forward is the same migration work — it simply needs to happen under more time pressure, since your tracking is actively degraded in the meantime rather than just at risk.

 

 

Frequently Asked Questions