> ## Documentation Index
> Fetch the complete documentation index at: https://docs.stigg.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Custom add-ons

Custom add-ons are used when the price and content of subscriptions are negotiated individually with each customer, typically in sales-led opportunities.

Because add-ons extend plans, subscriptions that include custom add-ons must also include a [custom plan](../../modeling-your-pricing-in-stigg/plans#custom-plans).

When Stigg is integrated with a billing solution, subscriptions that include custom plans and add-ons will **not** be created in the billing system.

To set an add-on as Custom:

1. Select **"Custom"** as the add-on type.
2. Click **"Continue"** to proceed.