> For the complete documentation index, see [llms.txt](https://developer.paddle.com/llms.txt).

# Store your own custom data against discounts

Attach your own key-value data to discounts in Paddle when working with the API.

---

## What's new?

We updated [discount](https://developer.paddle.com/api-reference/discounts/overview.md) entities so that now you can add `custom_data` when creating or updating them.

- **custom_data** (object): Your own structured key-value data

## How it works

[Custom data](https://developer.paddle.com/api-reference/about/custom-data.md) lets you add your own key-value data to entities created using [Paddle Checkout](https://developer.paddle.com/concepts/sell/self-serve-checkout.md) or the API. Once added, you can see custom data in API responses and webhooks for an entity.

Previously, you could add custom data to [transaction](https://developer.paddle.com/api-reference/transactions/overview.md), [subscription](https://developer.paddle.com/api-reference/subscriptions/overview.md), [product](https://developer.paddle.com/api-reference/products/overview.md), and [price](https://developer.paddle.com/api-reference/prices/overview.md) entities. We recently added the option to add custom data to [customer, address, and business entities](https://developer.paddle.com/changelog/2023/custom-data-customers-addresses-businesses.md). With this update, you can add custom data to discount entities, which means all core entities in the Paddle API support custom data.

This is especially useful if you're using the API or webhooks to sync with a CRM or ERP solution. You can store identifiers or other data from your third-party solution against related entities in Paddle.

## Next steps

This change is available in version `1` of the Paddle API.

It's a non-breaking change, meaning it doesn't impact existing integrations.

Create or update [discounts](https://developer.paddle.com/api-reference/discounts/overview.md) using the API to get started.
## Summary of changes

| Name | Type | Change | Entity | Description |
| --- | --- | --- | --- | --- |
| `custom_data` | Field | updated | Discount | Now writable on create and update. |