You can configure customizable Bundles so that additional products can be added to the Bundle subscription. Like the main bundle configuration, these add-ons are configured through the use of a Shopify Collection. You can configure add-ons to add extra items as one-offs or with each delivery. 

This guide provides the steps to create an add-on collection and add it to the Bundles setup. 

Before you start

• Add-ons and extras can only be added to customizable bundles.
• Recurring add-ons are individual subscriptions that follow the same delivery frequency as your bundle.

• It’s not possible to set up recurring add-ons with dynamically-priced bundles and only extras will appear in the bundles settings. If you want to include recurring add-ons with dynamically-priced bundles, it’s recommended to create an add-on collection and make it part of the bundle. 

• Add-on subscriptions are managed in the customer portal separate from the bundle subscription.
• Customers can skip, cancel, and update their add-on subscription just like any other regular subscription.
• Add-on products must have the same subscription rules as the bundle configured on Recharge. 
• One-off extras are products that are added to the first order only. 
• There are no quantity limits on add-ons and extras. Customers are able to add as many items as they want.

Step 1 - Setup products and collection in Shopify

Before adding to the bundle, create the add-on products and an add-on collection in Shopify. 

1. Create the product(s) in Shopify that can be used for add-on.
2. Create your add-on collection in Shopify.

Optional - Step 2 - Add products to Recharge

Recurring add-on products must have the same rules as the main bundle product. If the bundle is configured as one-time and subscription, the add-on products must follow the same cadence.

Create subscription rules for the add-on products in Recharge, if necessary, to match the Bundle configuration.

The add-on product must exist in Recharge and have the same frequency as the parent bundle product to be eligible for purchase.

Step 3 - Select add-ons for the bundle

Once the add-on collection is created, you can add it to the bundle on Recharge. 

1. In the merchant portal, click Products and select Bundles.
2. Click the pencil icon on the specific bundle and select Got it to confirm you'd like to proceed with editing the bundle.
   
3. Click Add beside Cross-sells under the additional settings section. 
   
4. Use the checkbox to determine the add-on setting. Both options can be selected to provide customers with the option to choose how they would like to configure their add-ons.
   • Add one-off extras to the first delivery - Subscribers will only get these extras once, with their first delivery.
   • Add repeating add-ons to every delivery - Subscribers will get these add-ons with every delivery until they remove them.
5. Click Select beside the add-on collection and click Save changes to confirm.