# Billing Account API - Register Payment PIN

## 1. API Overview

### Purpose

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***This API registers the authentication PIN used for card-based payments.<br>The PIN provided by the user **must be transmitted in an encrypted form**, and EBP does not interfere with the encryption method.<br>The purpose is to enhance security by combining registered card data with a PIN without exposing sensitive card information.***
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> **Note**: Changing the payment PIN is not supported. If you lose your PIN, you must delete the existing payment method and re-register.

### Details

[table:key-value]
| Item | Value |
| :-------------- | :--------------------------------- |
| **API Name**    | Register Payment PIN |
| **API Path**    | /api/v2/payment-methods/pin/registration |
| **API ID**      | EBP_API_131 |
| **HTTP Method** | [badge:POST,blue,lg]               |
| **Region** | [badge:Global,green-subtle,lg] |
[/table]

### 2.1 Request Header

@@include:common-headers-link.md@@

### 2.2 Request Data Schema

| Field      | Details & Description                                                   |
|------------|-------------------------------------------------------------------------|
| userNo     | [type:string] [req:Yes] [desc:Internal user number for tracking purposes] |
| paymentMethodId    | [type:string] [req:Yes] [desc:Unique identifier for the Payment Method] |
| paymentPin | [type:string] [req:Yes] [desc:PIN to register for token-based payment]  |

### 2.3 Request Examples

#### JSON Example

```json
{
  "userNo": "T0a8w9h7t5h3v5w6w4v6v4d1d4c1",
  "paymentMethodId": "202512110245491",
  "paymentPin": "44a019096dabfb5c660df1252609528795400f653ba"
}
```

## 3. Response Specification

### 3.1 Response Data Schema

#### Response Data Schema

@@include:standard-response.md@@
| -1 | data | [type:object] [desc: null]            |
| 0 | paymentMethodId | [type-size:string,16] [req:Yes] [desc:Token identifier (for server internal/external tracking)]                      |

### 3.2 Response Samples

#### Success Response

```json
{
  "resultCode": "0",
  "message": "SUCCESS",
  "requestId": "06EFX0CRR7JK0KCSSTFEEDRDVG",
  "timestamp": "2025-12-30T07:33:13.824093100Z",
  "data": {
    "paymentMethodId": "b79c2955f3a7462f86885c2d7fae04b5"
  }
}
```