Custom discounts on POS 11.5 and extensions

Extensions
1

One of our clients received the following (see quoted), about changes to custom amount in discounts in POS (which I totally agree with), but surprisingly not sent in a development email…

Our POS app extension (in a public app) will be affected, my questions are:

  1. If we stay on the current POS extension API version, will the custom amount be wrong?
  2. Do we need to determine the client’s POS version to decide what amount to apply?
  3. Are we forced to update to POS UI extension 2026-07, which is a release candidate at the moment.
  4. How do we test this? Is there a developer preview for POS?

Custom discount amounts on line items are changing in POS

Starting on April 27, 2026, with version 11.5 of Shopify POS, there will be changes to how custom discount amounts are applied to line items.

…

Important: Action may be required for POS extensions that apply discounts
If you use a custom POS extension that applies custom discounts programmatically, work with your development team to update ahead of v11.5. The EACH allocation behaviour takes effect natively with API version 2026-07 and above. Extensions targeting this version should be updated to pass EACH allocation directly. This gives you explicit control over per-unit discount going forward.

Please advise on the actions we should take.

2

Is there any answer to my question? TLDR: Will new POS version affect the behavior for the current POS extension with custom discount? I.e. Total amount discount vs amount per quantity.