How Percentage Fees Work
The Percentage Fee type in our app uses Shopify's Cart Transform API (CTA) to improve loading speed and overall performance. This allows percentage-based fees to be applied seamlessly without delays or page reloads and without the need to create cloned products.
How the App Handles Percentage Fees
Cart Fees vs. Product Fees
- Cart Fee:
- When you create a Cart fee, the app generates a wrapper product (by default called "Additional fees").
- All applied percentage-based fees appear as sub-products inside this wrapper at checkout.
- In the order admin, fees are listed as separate products, without the wrapper.

- Product Fee:
- When you create a Product fee, the fee is merged with the master product instead of being stored inside the "Additional fees" wrapper.
- At checkout, the wrapper product will take the name of the master product and include two items inside it:
- The original product
- The fee as a sub-product
- In the order admin, a fee and the master product are listed as separate products.

Managing the Wrapper Product
- You can find the wrapper product in your Products list under the type mws_fee_generated.
- It can be modified as needed (rename, upload an image, etc.).
- Important: If you disable or archive this product, all percentage fees will automatically become inactive.

How the App Stores Percentage Fees
- In addition to the wrapper product, the app also generates a corresponding "mws_fee_generated" product for each individual percentage fee.
- These fee products are stored inside the wrapper and act as sub-products at checkout.
How to Move to CTA Mode for Percentage Fees
If you already have percentage fees created using legacy approaches, you can switch them to CTA mode individually.
To do this:
- Open the Fee Admin for the percentage fee you want to update.
- Scroll down to the bottom of the page to find the Advanced Fee Settings section.
- Check the box for "Shopify Cart Transform API (Recommended)."