A Product reference option lets you offer another product from your store as a choice on a main product's page — a matching accessory, a warranty product, a care kit, or a bundled companion item. If you searched for a Shopify product add-on option or a linked product option, this guide shows how to set one up in a few minutes with Optionify, a free product options app.
How do I offer another product as an add-on option in Shopify?
Shopify's native variants can only describe the current product — they can't reference other products in your catalog. With Optionify, create an option set, add a Product reference option, select the products from your store you want to offer, assign the set to your main products, and enable the theme app embed. Each linked product then appears as a selectable choice on the page.
Linked products offered as selectable add-on choices on a live product page
How the referenced product appears as a choice
When you add a Product reference option, you pick which products from your store to offer. Each one you select becomes a choice inside the option on the main product's page, tied to the real catalog item rather than a label you typed by hand. That keeps the add-on connected to an actual product you sell — its name stays in sync with your catalog, and the add-on is unambiguous for both the customer and your fulfillment team.
Because these choices live outside the variant system, they don't create SKUs or count against Shopify's 3-options-per-product limit, so you can offer several linked add-ons on a single product.
How to set up a product reference option in Optionify
- Click Create option set and name the set (e.g. "Recommended add-ons").
- Add an option and choose the Product reference type.
- Enter the option label, such as "Add a matching accessory" or "Protect your purchase."
- Select the products from your store you want to offer as choices.
- Give each choice an add-on price if it should charge extra (details below).
- Decide whether the option is required — usually optional for cross-sells.
- Assign the set with the right assignment method — All Products, Tagged Products, Collections, or Individual Products.
- Set the set to Active and save with Shopify's save bar.
Selecting store products as choices and setting add-on prices in the Option Set Editor
Linked choices only appear on the storefront once the theme app embed is enabled in your theme editor, so switch it on before testing.
Can a linked product add-on charge extra?
Yes. A Product reference choice can carry an add-on price in one of two modes:
- Fixed — a set amount, e.g. "Add care kit (+$19.00)."
- Percent — a percentage of the main product's price, e.g. "Add 2-year warranty (+10%)."
The add-on charge carries to checkout through a hidden companion product, so it works with Buy it Now and Shop Pay too. See pricing variants for how the total reaches the order and charging extra for an option for more pricing patterns.
Product reference vs. checkbox add-ons
Both offer extras, but they're built differently:
- Checkbox add-ons — you type each extra as a value with its own price. Best for simple options like "Gift wrap" or "Extra battery" that aren't full catalog products.
- Product reference — you link to an actual product in your store as the choice. Best when the add-on is a genuine product you sell and want to keep connected to your catalog.
If the add-on is a real product with its own page and details, use a product reference. If it's a small extra that doesn't warrant its own product, a checkbox is simpler.
Real use cases for linked product add-ons
Matching accessories. A phone product offers a case and a charger — both real products in your store — as selectable add-ons on the product page.
Warranty and protection products. A store links a warranty product as a choice, letting customers add coverage without leaving the page.
Care kits and consumables. A furniture or footwear store offers a cleaning or care kit as a linked add-on to the main item.
Curated bundles. A gift or beauty shop links complementary products as choices, building a soft bundle without creating a separate bundle SKU.
For broader cross-selling patterns and how add-on charges flow to the order, see Shopify product add-ons on the product page. Because every choice is saved as a line item property on the order, your fulfillment team sees exactly which linked products the customer added.
FAQ
How do I offer another product as an add-on option in Shopify? Shopify variants can't reference other products. With Optionify, create an option set, add a Product reference option, select products from your store, assign the set to your main products, and enable the theme app embed.
How does the referenced product appear to customers? Each linked product shows up as a choice within the option, so customers add it from the main product page. It uses the real product you selected, keeping the add-on tied to a catalog item.
Can a linked product add-on charge extra? Yes. A Product reference choice can carry a fixed amount or a percentage of the main product's price, and the charge carries through to checkout, including Buy it Now and Shop Pay.
Does a product reference option create variants? No. It lives outside the variant system, so it never creates SKUs or counts against Shopify's 3-options-per-product limit.
How is this different from a checkbox add-on? A checkbox lists extras you type as values. A product reference links to an actual product in your store, so the add-on stays connected to a real catalog item.
Get started with Optionify
Want to offer real products from your store as add-on choices? Install Optionify — it's free, forever, with all 17 option types, per-choice pricing, and product references included.
Install Optionify on the Shopify App Store
New here? Start with creating your first product option, then compare checkbox add-ons for simpler extras and see Shopify product add-ons for the full cross-sell playbook.