**Last updated**: 14 May 2025 | [**Change log**](/products/balance/changelog/)

# Get started

Make yourself familiar with our [API Principles](/products/reference/api-principles) to ensure a resilient integration.

## Set your headers

Setting your headers is an important part of an API request. The headers represent the meta-data associated with your API request.


```
Authorization: {your_credentials}
Content-Type: application/vnd.worldpay.accounts.balance-v1+json
Accept: application/vnd.worldpay.accounts.balance-v1+json
```

| Header | Description |
|  --- | --- |
| `WP-CallerId` and/or `X-WP-Diagnostics-CorrelationId` | ID of the consumer. This value is optional and provided by you. It should be unique per each consumer. If both WP-CallerId and X-WP-Diagnostics-CallerId are included in the request, then WP-CallerId is used. If not provided, it is generated, since it is required for traceability. |
| `WP-CorrelationId` and/or `X-WP-Diagnostics-CorrelationId` | ID of the request which may be used between you, the API and downstream services. If both WP-CorrelationId and X-WP-Diagnostics-CorrelationId are included in the request, then  we use WP-CorrelationId. If not set in either `WP-CorrelationId` nor `X-WP-Diagnostics-CorrelationId`, a new correlationId is generated, since the correlationId is required for traceability. |
| `Authorization` | We use the `Authorization` header to identify and authenticate you within Access Worldpay. You **must** use the `Authorization` header for any request you send to our Account APIs. |
| `Content-Type` | We require the `Content-Type` header if the request you're sending includes a request body, and if the HTTP method is a `POST` or a `PUT`. |
| `Accept` | We use the `Accept` header to identify which version of our API you are using. You **must** use the `Accept` header for any request you send to our Account APIs. |


If you're using both the `Content-Type` and `Accept` headers, they must match.

Note
Replace `{your_credentials}` with your base64-encoded Basic Auth username and password. To get your Access Worldpay credentials contact your Implementation Manager.

## DNS whitelisting

Whitelist the following URLs:

* `https://try.access.worldpay.com/`
* `https://access.worldpay.com/`


Please ensure you use DNS whitelisting not explicit IP whitelisting.

### Link caching

Note
When you make a request within Access Worldpay, you should always cache the response returned.

**Next steps**

[Get balance/account details](/products/balance/v1)