Shopify “Continue selling when out of stock” and Essential Preorder

If you use Essential Preorder to show a Preorder button, Shopify’s Continue selling when out of stock setting may need to be enabled or disabled, depending on your campaign.

This article explains what the setting does in Shopify, where to find it, and how it affects your Preorder button.

What “Continue selling when out of stock” means in Shopify

Shopify tracks inventory per variant. When a variant’s available inventory reaches 0, it is out of stock.

The Shopify setting Continue selling when out of stock (sometimes shown as Sell when out of stock) controls whether customers can still buy at 0:

• Off: Shopify blocks purchase at 0. The item cannot be added to cart.
• On: Customers can still buy at 0. This allows out-of-stock purchases (including preorders).

This setting is usually managed per variant, not just per product.

Where to find this setting in Shopify

1. Go to Shopify admin

2. Open Products

   Open the product (and the correct variant, if you have variants)

   In the Inventory section, look for:

   • The pill Sell when out of stock: On/Off, or
   • More details → Continue selling when out of stock

How Essential Preorder uses this setting

In your campaign, you choose when to show the Preorder button. Here is how each option works.

1) Show Preorder button when product is out of stock

• The Preorder button shows when the variant inventory reaches 0
• It switches back to Add to cart when inventory is above 0
• Shopify Continue selling when out of stock must be On for the Preorder button to show at 0

Optional: Limit inventory for all products

If you enable Limit inventory for all products, you set a single limit for the campaign.

• When the limit is reached, Essential Preorder switches Continue selling off so the product cannot be oversold
• This applies in both Automatic and Manual modes

2) Always show Preorder button

• The Preorder button replaces Add to cart regardless of stock level
• If a variant is out of stock (inventory 0), Shopify Continue selling when out of stock must be On or customers cannot buy

3) Show Preorder button when product is in stock

• The Preorder button shows only when inventory is above 0
• When inventory is 0, Preorder does not show
• Shopify Continue selling when out of stock must be Off

Automatic vs Manual control in Essential Preorder

In the campaign section Continue selling when out of stock, you can choose how the Shopify setting is managed.

Automatic (recommended)

Essential Preorder manages the Shopify setting automatically while the campaign is published.

What it does depends on your “Show preorder button” selection:

• When product is out of stock: turns on Continue selling at inventory 0 or below
• Always: turns on Continue selling always
• When product is in stock: turns off Continue selling always

Manual

You manage the Shopify setting in Shopify.

• If the Shopify setting is not set correctly for a variant, the Preorder button may not show as expected.
• To avoid overselling, turn off the Shopify setting for an unpublished campaign.
• In the campaign you can use Turn OFF now once to switch it off for products in this campaign.

Common reasons the Preorder button still does not show

• You are viewing a different variant than the one included in the campaign
• The product is not available on the Online Store sales channel
• A theme or another app replaces the product form (cart drawer, bundles, product options), so the button is not rendering in the expected place