---
title: "Sender eKYC (Biometric) API Reference"
description: "Initiate biometric Aadhaar eKYC to verify and upgrade a DMT sender's account."
canonical: "https://eps.eko.in/docs/dmt-fino-sender-ekyc"
---


> **Canonical URL:** https://eps.eko.in/docs/dmt-fino-sender-ekyc
> This is a machine-readable Markdown version of the page for AI agents and LLMs. The primary (HTML) version lives at the canonical URL above.

# Sender eKYC (Biometric) API Reference

`PUT https://staging.eko.in/ekoapi/v3/customer/payment/dmt-fino/sender/{customer_id}/otp`

Initiate biometric Aadhaar eKYC to verify and upgrade a DMT sender's account.

**Behaviour**

- **Sends OTP**: Sends an SMS to the customer; repeating the call sends another.
- **[₹11.00 incl. GST / new sender](https://eps.eko.in/pricing?tab=dmt#dmt-calculator)**: Charged once per newly registered sender; a repeat KYC is free.

Performs biometric eKYC using fingerprint data linked to the sender's Aadhaar number. Requires a compatible RD-service device; the PID XML is captured at the agent's terminal and submitted with the sender's Aadhaar number (include the `wadh` value when generating the PID). On success the system dispatches an OTP for confirmation; call Validate eKYC OTP next. A successful eKYC upgrades the sender's monthly limit from ₹5,000 to ₹25,000.

To capture the `piddata` PID block with an RDService-compliant fingerprint scanner, see the [Aadhaar Biometric Authentication guide](/docs/aadhaar-biometric-rdservice).

> View product & pricing details: [Domestic Money Transfer (DMT)](https://eps.eko.in/products/dmt-api.md)

## Path parameters

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| customer_id | string | yes | Sender's 10-digit mobile number. e.g. 9123456789 |

## Body parameters

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| initiator_id | string | yes | Registered mobile number of the API user (see Platform Credentials). e.g. 9962981729 |
| client_ref_id | string | no | Unique reference ID per API call, generated by your system (10–20 characters; 10 recommended). The SDKs generate one for every non-GET call when you don't. e.g. 2026010100123456789 |
| aadhar | string | yes | 12-digit Aadhaar number of the sender. e.g. 234567890123 |
| piddata | string | yes | XML-encoded biometric PID data captured from a certified biometric device (fingerprint scanner). e.g. <PidData><Resp errCode="0" errInfo="Capture Success" .../></PidData> |

## Headers

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| developer_key | string | yes | Static API key issued to your account after KYC. |
| secret-key | string | yes | Dynamic per-request signature: base64(HMAC-SHA256(timestamp, base64(access_key))). |
| secret-key-timestamp | string | yes | Current time in milliseconds since UNIX epoch, used to compute secret-key. Must match server time. |
| content-type | string | yes | application/json e.g. application/json |

## Response

⭐ marks fields highlighted as verifiable.

| Field | Type | Description |
| --- | --- | --- |
| status | number | Primary success indicator (0 = success). |
| message | string | Human-readable response / error message. |
| response_status_id | number | UI display hint only (-1/0 success, 1 failure, 2 initiated, 3 refund initiated, 4 refunded). Never branch on it — use `status` (and `tx_status` for financial APIs), or `response_type_id` where documented. |
| response_type_id | number | A unique id for every possible response shape (success or error) — useful for client logic branching and analytics. |
| data | object | API-specific response payload. |
| data.user_code | string | Agent user code associated with the KYC request. |
| data.intent_id | string | Reserved intent identifier (empty in the standard flow). |
| data.kyc_request_id ⭐ | string | Unique identifier for this KYC request. Required for the Validate eKYC OTP step. |
| data.otp_ref_id ⭐ | string | Reference ID for the OTP sent to the sender's Aadhaar-linked mobile. Required for the Validate eKYC OTP step. |

## Response types

Branch on `response_type_id` to decide the next call:

| response_type_id | Meaning | Next step |
| --- | --- | --- |
| 2129 | OTP sent — proceed to Validate eKYC OTP | [dmt-fino-validate-ekyc-otp](https://eps.eko.in/docs/dmt-fino-validate-ekyc-otp.md) |

## Example request

```json
{
  "initiator_id": "9962981729",
  "client_ref_id": "2026010100123456789",
  "aadhar": "234567890123",
  "piddata": "<PidData><Resp errCode=\"0\" errInfo=\"Capture Success\" .../></PidData>"
}
```

## Example response

`response_type_id` `2129` — OTP sent — proceed to Validate eKYC OTP. Next step: [dmt-fino-validate-ekyc-otp](https://eps.eko.in/docs/dmt-fino-validate-ekyc-otp.md).

```json
{
  "status": 0,
  "response_status_id": 0,
  "message": "Validate the OTP",
  "response_type_id": 2129,
  "data": {
    "user_code": "10472151",
    "intent_id": "",
    "kyc_request_id": "9332126",
    "otp_ref_id": "666803844"
  }
}
```

## Error scenarios

| Status | response_type_id | Scenario |
| --- | --- | --- |
| 200 | `2135` | Incorrect PID data — eKYC verification failed |
| 200 | `2135` | Sender already has an existing relationship with the bank |