> For the complete documentation index, see [llms.txt](https://options-docs-v2.avisplus.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://options-docs-v2.avisplus.io/get-started/key-terminology-simplified/add-on-product-add-charge.md). # Add-on product (Add charge) The **Add-on product** feature allows you to automatically apply an additional cost based on the customer's selection of an option value. When this feature is enabled, selecting a specific option value generates an additional charge that increases the product's total price. This is useful for options that come with a price increase, such as premium materials or custom features. The **Add Charge** ensures that the additional cost is applied seamlessly during the checkout process, reflecting the total price according to the customer's choices. {% hint style="info" %} [How to set up Add-on product (Add charge) for your options](https://options-docs-v2.avisplus.io/app-features/up-charge-for-specific-variants) {% endhint %}