Shopify is retiring Shopify Scripts — the legacy system used for custom checkout, discount, and shipping logic. The replacement is Shopify Functions, a more powerful, more flexible system. Scripts will stop executing on their deprecation dates. If your store relies on them, migration is mandatory — not optional.
Volume discounts, BOGO, tier pricing → Shopify Discount Functions.
Custom rates, free-shipping thresholds → Shipping Functions.
Payment method filtering, gateway routing → Payment Functions.
Auto-add gifts, product transforms → Cart Transform Functions.
Banners, validation, line item info → Checkout Extensibility apps.
We connect to your store, list every active Script, and document its logic. Output: a script-by-script migration plan with risk and effort.
Each Script mapped to its Functions equivalent. Some are 1:1; some need a checkout extension; a few need a private app. We tell you which up front.
Functions developed in Rust + JS. Unit tested. Deployed to a dev store mirror. Every discount/shipping scenario reproduced.
Merchant reviews each Function in a live preview. Edge cases run end-to-end (discount stacking, refunds, draft orders).
Functions deployed live. Scripts disabled tier-by-tier. 14-day monitoring window for refund and order anomalies.
1–3 Scripts. Discounts or shipping. No checkout customisation.
4–8 Scripts. Mixed discount + shipping + payment logic.
8+ Scripts plus custom checkout logic. Plus stores with bespoke flows.
* INCLUDES 30-DAY POST-MIGRATION SUPPORT · ZERO DOWNTIME · UAT BEFORE GO-LIVE
Shopify has staged Scripts deprecation in motion across 2025–2026, with specific Script types (Discount, Shipping, Payment, Line Item) being retired on different dates. We audit your store and tell you the exact deadline for each Script you have so you know which to migrate first.
Yes. On the deprecation date for each Script type, that Script stops executing — silently. Discounts will not apply, shipping rates will not calculate, payment filters will not fire. Customers will see broken behaviour you cannot debug from the Shopify admin.
Yes — and we recommend it. The Shopify Functions architecture is more flexible than Scripts. We often consolidate logic that Scripts had to spread across multiple files into a single, cleaner Function with proper testing and observability.
No — that is the good news. Shopify Functions are available on all plans, including Basic, Shopify, and Advanced. Scripts (the legacy thing being deprecated) were Plus-only. Many Basic-tier stores will gain capability they never had before.
For Shopify Plus stores using checkout.liquid customisation, we migrate to Checkout Extensibility apps. Different mechanism, similar capability — and far more maintainable. Most checkout.liquid behaviour can be replicated; some niche cases (e.g. fully bespoke layouts) may need a redesign.
Most stores: 2–6 weeks. Single-Function migrations (one discount, one shipping rule): 1–2 weeks. Complex multi-Script Plus stores with checkout.liquid + 8+ Scripts: 4–8 weeks. We can quote within 48 hours of seeing your Scripts inventory.
Basic Functions migration starts from £2,999 for up to 5 Functions. Plus migrations with checkout.liquid + bespoke logic typically range £6,500–£14,999 depending on complexity and number of Functions. We quote fixed-price after a 30-minute scoping call.
No — every Function ships behind a feature flag and is tested in a staging environment before cutover. We schedule cutover off-peak (typically Tuesday morning UK time) with the legacy Script staying active until the Function is verified live.
Yes. Functions execute in WebAssembly with strict latency budgets enforced by Shopify (5ms for most types). Scripts had no such limit and could slow checkout. In practice we see 30–60% reduction in checkout-step latency on stores migrating from heavy Script usage.
Send your store URL — we'll audit your active Scripts and tell you exactly which need migration, when, and at what cost. No obligation.