# Adding billing details to a payment

**Audience:** All users (Merchants, Developers, Testers)

**Environment:** Sandbox / Production

## Introduction

Sometimes you want your payments to be linked to a specific customer who visited and purchased a product from your website.
With Helix-Pay, this is really easy.

## Using the API

1. Use the `POST /payments` endpoint as usual
2. Send a `billing_address` property as part of the request body


### Example


```javascript
{
  "amount": 2498,
  "currency": "GBP",
  "description": "Order #10001",
  "billing_address": {
    "first_name": "John",
    "last_name": "Doe",
    "email": "john.doe@test.com",
    "phone_number": "+447975112233",
    "address_line_1": "123 Queen Str.",
    "address_line_2": "Apartment Block 2",
    "city": "London",
    "state": "London",
    "zip_code": "E1 7BT",
    "country_code": "GB"
  }
}
```

### Billing Address Definition

Here is the definition of a billing address. It is written as a Typescript interface, but it can be adapted to any programming language.


```ts
interface BillingAddress {
  first_name: string;
  last_name: string;
  email: string;
  phone_number?: string; // optional
  address_line_1: string;
  address_line_2?: string; // optional
  city: string;
  state: string;
  zip_code: string;
  country_code: string;
}
```

## Checking for billing address

Once you create a payment that has a billing address, you can see it in the Helix-Pay portal, as part of the
payment details page.