---
title: "Registers a new user or update an existing user"
method: POST
path: "/merchants/{mid}/users/{uid}"
---

# Registers a new user or update an existing user

`POST /merchants/{mid}/users/{uid}`

## Request

- Base URL: `https://api.test.kalixa.com/api/v4`
- URL: `https://api.test.kalixa.com/api/v4/merchants/{mid}/users/{uid}`
- Auth: none declared

Registers a new user or update an existing user

## Path parameters

- `mid` string, required
- `uid` string, required

## Request body

- UserData
  - `username` string, required
  - `firstname` string
  - `lastname` string
  - `currencyCode` string
  - `languageCode` string, required
  - `email` string
  - `dateOfBirth` string, date
  - `identificationNumber` string
  - `identificationNumberType` string
  - `drivingLicenseNumber` string
  - `drivingLicenseIssuingState` string
  - `gender` string
  - `address` Address, required
    - `street` string
    - `houseName` string
    - `houseNumber` string
    - `houseNumberExtension` string
    - `postalCode` string
    - `city` string
    - `State` string
    - `countryCode` string
    - `telephoneNumber` string

## Response `200`

Successful operation

- UserResponse
  - `user` User
    - `id` number
    - `externalId` string
    - `firstname` string
    - `lastname` string
    - `username` string
    - `languageCode` string
    - `email` string
    - `dateOfBirth` string, date
    - `gender` string
    - `address` Address
      - `street` string
      - `houseName` string
      - `houseNumber` string
      - `houseNumberExtension` string
      - `postalCode` string
      - `city` string
      - `State` string
      - `countryCode` string
      - `telephoneNumber` string

## Other responses

- `400`: Invalid data supplied

---

[API](https://skmtc.dev/kalixa/apis/payment-service-v4.md) - [All operations](https://skmtc.dev/kalixa/apis/payment-service-v4/llms.txt) - [OpenAPI document](https://skmtc.dev/kalixa/apis/payment-service-v4/revisions/5b7869243a54?raw)