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

# Store your own custom data against customers, addresses, and businesses

Attach your own key-value data to customers, addresses, and businesses in Paddle when working with the API.

---

## What's new?

We updated [customer](https://developer.paddle.com/api-reference/customers/overview.md), [address](https://developer.paddle.com/api-reference/addresses/overview.md), and [business](https://developer.paddle.com/api-reference/businesses/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 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. Now you can add custom data to customer, address, and business entities, too.

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 [customers](https://developer.paddle.com/api-reference/customers/overview.md), [addresses](https://developer.paddle.com/api-reference/addresses/overview.md), and [businesses](https://developer.paddle.com/api-reference/businesses/overview.md) using the API to get started.
## Summary of changes

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