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

# Vessels by IMO or MMSI

> Find all vessels matching a given IMO or MMSI number. Use this when you receive an unexpected vessel to identify the correct one. Vessels may change ownership and have their numbers re-registered. Free endpoint (0 credits). Rate limit: 50 requests/min.

Find all vessels matching a given IMO or MMSI number. Use this endpoint when you receive an unexpected vessel in response to help identify the correct vessel.

<Info>
  **Credits:** 0 credits (free endpoint)
</Info>

## When to Use This Endpoint

Sometimes a vessel changes ownership, and some of its numbers are changed and re-registered. If you made a request and received a different vessel than expected:

1. Use this endpoint with your IMO or MMSI
2. Review the list of all vessels with similar parameters
3. Select the correct vessel and use its MMSI for subsequent requests

<Tip>
  If you still can't find the vessel you're looking for, please [contact support](https://datadocked.com/contact) and we'll help resolve this.
</Tip>

## Response Fields

Each vessel in the response includes:

* `name`: Vessel name
* `mmsi`: Maritime Mobile Service Identity
* `imo`: IMO number


## OpenAPI

````yaml GET /vessels-by-imo-or-mmsi
openapi: 3.1.0
info:
  title: Data Docked Maritime API
  description: >-
    A comprehensive maritime data API providing real-time vessel tracking, port
    operations, inspection data, and more. Access AIS data, vessel particulars,
    management information, and historical tracking data.
  version: 1.0.0
  contact:
    name: Data Docked Support
    url: https://datadocked.com/contact
servers:
  - url: https://datadocked.com/api/vessels_operations
    description: Production server
security:
  - apiKey: []
tags:
  - name: Account
    description: Account management endpoints
  - name: Vessel Operations
    description: Vessel data, location, and tracking endpoints
  - name: Port Operations
    description: Port calls and port data endpoints
paths:
  /vessels-by-imo-or-mmsi:
    get:
      tags:
        - Vessel Operations
      summary: Vessels by IMO or MMSI
      description: >-
        Find all vessels matching a given IMO or MMSI number. Use this when you
        receive an unexpected vessel to identify the correct one. Vessels may
        change ownership and have their numbers re-registered. Free endpoint (0
        credits). Rate limit: 50 requests/min.
      operationId: getVesselsByImoOrMmsi
      parameters:
        - name: imo_or_mmsi
          in: query
          required: true
          description: The IMO or MMSI number to search for matching vessels.
          schema:
            type: string
          example: '9870666'
      responses:
        '200':
          description: Successful response with matching vessels
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/VesselsByImoOrMmsiResponse'
              example:
                vessels:
                  - name: NORMA
                    mmsi: '210048000'
                    imo: '9870666'
                  - name: NORMA2
                    mmsi: '210048001'
                    imo: '9870666'
        '400':
          description: Bad request - Invalid IMO/MMSI format
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
        '401':
          description: Unauthorized - Invalid or missing API key
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
components:
  schemas:
    VesselsByImoOrMmsiResponse:
      type: object
      properties:
        vessels:
          type: array
          items:
            type: object
            properties:
              name:
                type: string
                description: Vessel name
              mmsi:
                type: string
                description: Maritime Mobile Service Identity
              imo:
                type: string
                description: IMO number
    Error:
      type: object
      properties:
        error:
          type: string
          description: Error type
        message:
          type: string
          description: Error message
  securitySchemes:
    apiKey:
      type: apiKey
      in: header
      name: x-api-key
      description: >-
        Your personal API key found in your profile dashboard at
        https://datadocked.com/dashboard/my_keys

````