> ## Documentation Index
> Fetch the complete documentation index at: https://docs.useagentbank.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Update end-user KYC

> Apply a versioned partial KYC update to a merchant end user.

```text theme={null}
PUT /v1/partner/end-users/:endUserId/kyc
```

**Authentication:** signed Partner API request.

## Path parameters

| Parameter | Required | Description |
| - | - | - |
| `endUserId` | Yes | AgentBank-generated `peu_...` ID owned by the signed merchant. |

## Request body

`base_kyc_version` must be the version from the latest end-user read. `kyc` is
a partial patch: omitted fields remain unchanged, while `null` and unknown
fields are rejected.

```json theme={null}
{
  "base_kyc_version": "1",
  "kyc": {
    "contact": {"phone_e164":"+84999999999"}
  }
}
```

## Response

```json theme={null}
{
  "end_user_id": "peu_6fa6b3ee9bfe43db8700b04e8c91cc0b",
  "status": "provider_processing",
  "kyc_version": "2",
  "kyc_summary": {"schema_version":"partner_end_user_kyc_v1","nationality":"VN"},
  "rail_readiness": [{"fiat_currency":"VND","state":"pending","reason_code":null,"expires_at":null}],
  "updated_at": "1787000000000"
}
```

On a KYC version conflict, read the end user, merge only allowed changes, and
send a new patch. Do not retry a stale version unchanged.