Why isn't my discount working on preorder products? (Essent Preorder Back in Stock app)

Shopify discount codes don't apply

Shopify treats preorders like subscriptions for discounts. Open the discount in Shopify admin → Discounts and set Purchase type to Both (or Subscription). Save.

Exception: if the campaign has Use Shopify selling plan turned off, preorders are normal one-time purchases, so Shopify discounts apply as usual and the app's own discount fields are disabled.

Stop other discounts stacking on preorders

There's no app setting to block combining. In Shopify Discounts, set the other discounts' purchase type to one-time only, or exclude your preorder products, and check Combinations.

The preorder discount or strike-through price isn't showing

• Check the discount is set on the campaign's Content tab, and that Show discounted price and Strike through price are on in the Design tab.
• For collection pages and quick buy, also turn on Preorder discount under Preorder → Settings → General settings → Manage.
• App discounts need Shopify Payments and don't apply with express checkouts.
• Check in an incognito window. It's often browser cache.

Full guide: Why discounts may not work with preorders.