Shipping Discount Function – Controlling Checkout UI Display of Discounted Shipping Rate

Shopify Apps

Topic summary

Main issue: A Shipping Discount Function (built with Shopify Functions) correctly applies and calculates discounted shipping, but the checkout UI shows the original rate with a strikethrough above the discounted rate.

Observed behavior:

  • Checkout displays both the original shipping rate (crossed out) and the discounted rate.
  • Calculation and application of the discount are functioning as expected.

Desired behavior:

  • Show only the final discounted shipping price in checkout, hiding the original crossed-out rate.

Key question:

  • Is there any configuration, API setting, or controllable behavior within Shipping Discount Functions to change how shipping discounts are rendered in checkout?
  • Or is the checkout UI presentation fully controlled by Shopify and not customizable for shipping discounts?

Attachments:

  • A screenshot is provided to illustrate the current checkout display (important for understanding the UI issue).

Status:

  • No solution or confirmation yet. The thread is seeking guidance/official clarification; unresolved and open.
Summarized with AI on December 16. AI used: gpt-5.
1

Hi everyone,

We’re currently implementing a Shipping Discount Function using Shopify Functions.

The good news is that:

  • The shipping discount is applied correctly during checkout

  • The final discounted shipping amount is calculated as expected

However, we’re facing a checkout UI presentation issue.

Current Behavior

On the checkout page, Shopify displays:

  • The original shipping rate with a strikethrough

  • The discounted shipping rate below it

Requirement

We would like to display only the final discounted shipping price, without showing the original crossed-out rate in the checkout UI.

Question

Is there:

  • Any configuration,

  • API setting, or

  • Shipping Discount Function behavior

that allows controlling or overriding how shipping discounts are rendered in the checkout UI?

Or is this UI presentation fully handled by Shopify and not customizable when using Shipping Discount Functions?

We’ve attached a screenshot for reference.

Any guidance or confirmation from the community would be greatly appreciated.

Thanks in advance!