Locator Great Britain

Beta

Rank British outward postcodes by distance from a postcode or coordinates. Coverage is England.

OpenAPI reference
GEThttps://api.pro6pp.nl/v2/locator/gb

Overview

Returns your list of outward postcodes ordered by distance from an outward postcode or a lat/lng origin. Coverage is England.

Accepts outward postcodes such as B11 or SW1A, case-insensitive. Sectors such as B11 1 and complete unit postcodes such as B11 1AA are invalid. Each outward postcode is represented by the mean coordinates of its unit postcodes. Administrative labels are included only when every unit postcode shares the same non-null value for that field.

Supply either postalCode or both lat and lng. An outward postcode takes precedence over coordinates. straight measures from the supplied origin; road uses the origin's outward postcode, or the nearest outward centroid for a coordinate origin, and includes driving time. Results are ordered by distance unless orderBy=input is supplied.

ParametersQuery string

authKeystringRequired

Every request needs an API key, which you can get in the portal.

When you call the API from a browser, visitors can see your API key. Limit it to your own domains in the portal, or send the requests through your own server so the key stays hidden.

targetPostalCodesarray of stringRequired

Outward postcodes to rank, case-insensitive. For GET, separate them with commas, for example BS1,SW1A. For POST, supply a JSON array such as ["BS1", "SW1A"]. Sectors and complete unit postcodes are invalid.

Example
["BS1","SW1A"]
postalCodestring

An outward postcode such as B11 or SW1A, case-insensitive. Sectors such as B11 1 and complete unit postcodes such as B11 1AA are invalid. Supply either postalCode or both lat and lng. When both are supplied, the outward postcode's centroid is used as the origin.

Example
B1
Pattern
^[A-Za-z]{1,2}[0-9][0-9A-Za-z]?$
latnumber

The latitude.

lngnumber

The longitude.

orderBystring

The order in which to return the results: distance (default) or input (keeps the input ordering).

Default
"distance"
maxResultsinteger

The amount of results returned, a number between 1 and 999. Default value is 10.

Default
10
Min
1
Max
999
algorithmstring

Specifies the algorithm for calculating distance and time.

Available Algorithms:

  • straight: Calculates the distance in a straight line.
  • road: Calculates the actual traveling distance and time using the drive time matrix (shortest route) over the actual road network.
    • Availability of road depends on your subscription level.
Example
straight
Default
"straight"
One of
straightroad

Responses

200The supplied outward postcodes ordered from near to far, or an empty array when none matchList of results
FieldTypeExample valueDescription
distancenumber123600

Distance in metres, using the selected algorithm.

durationnumbernot in example

Driving time in minutes, included for the road algorithm.

latnumber51.453

Mean latitude of the outward postcode's unit postcodes.

lngnumber-2.594

Mean longitude of the outward postcode's unit postcodes.

postalCodestring"BS1"

The outward postcode, in uppercase.

countystringnot in example

The ceremonial county or unitary authority.

districtstringnot in example

The local authority district or borough.

civil_parishstringnot in example

The civil parish.

townstringnot in example

The town-level administrative area, present only where one exists.

settlementstringnot in example

The city, town or village name.

Example response
[
  {
    "distance": 123600,
    "lat": 51.453,
    "lng": -2.594,
    "postalCode": "BS1"
  },
  {
    "distance": 163138,
    "lat": 51.505,
    "lng": -0.132,
    "postalCode": "SW1A"
  }
]

Errors

Fields of an error response
FieldTypeDescription
error_idstring

The reason the request failed, such as INVALID_VALUE. The response lists the reasons this operation returns.

errorsarray of object

One entry per problem found in the request.

errors[].messagestring

A readable explanation of the problem, in English.

errors[].helpstring

A link to the documentation section that covers the problem.

errors[].parameterany

The parameter the problem is about. Usually its name; a list when several parameters are involved, or a name with the values to choose from when the request must select one.

errors[].valueany

The value the request sent for parameter, when it has one.

400Bad request
MISSING_PARAMETER

A parameter that other parameters depend on is missing. errors has one entry per missing parameter.

MISSING_PARAMETER
{
  "error_id": "MISSING_PARAMETER",
  "errors": [
    {
      "message": "Required parameter lat is missing",
      "help": "https://pro6pp.nl/docs/v2/redoc",
      "parameter": "lat"
    }
  ]
}
INVALID_PARAMETER_TYPE

A value has the wrong type, such as text for a number.

INVALID_PARAMETER_TYPE
{
  "error_id": "INVALID_PARAMETER_TYPE",
  "errors": [
    {
      "message": "parameter: lat has invalid 1,0, should be number",
      "help": "https://pro6pp.nl/docs/v2/redoc",
      "parameter": "lat"
    }
  ]
}
INVALID_VALUE

A required parameter is missing, or a value is malformed, out of bounds or cannot be found.

INVALID_VALUE
{
  "error_id": "INVALID_VALUE",
  "errors": [
    {
      "message": "value is invalid",
      "help": "https://pro6pp.nl/docs/v2/redoc",
      "parameter": "postalCode",
      "value": "invalid"
    }
  ]
}
401Unauthorized
UNAUTHORIZED

The API key is missing, unknown, revoked or expired, its subscription is not active, the request does not match the key's allowlist, or the subscription does not include this call.

UNAUTHORIZED
{
  "error_id": "UNAUTHORIZED",
  "errors": [
    {
      "message": "No authorization token provided",
      "help": "https://pro6pp.nl/docs/v2/redoc#section/Authentication"
    }
  ]
}

Code examples

curl "https://api.pro6pp.nl/v2/locator/gb?targetPostalCodes=BS1%2CSW1A&postalCode=B1&algorithm=straight&authKey=YOUR_API_KEY"

We encourage you to request example code in the language you prefer.

Step by step

Set up a quick form to try out the Great Britain Locator functionality by following the steps below.

  1. Build the HTML page

    We start by creating an empty HTML page, containing a minimal web page structure. Create a new .html file named pro6pp_great-britain_locator.html. Add the following code between the <body> and </body> tags. It adds the input fields for entering the address.

    pro6pp_great-britain_locator.html
    <form class="form" id="form">
      <div>Call</div>
      <div>
        <label for="targetPostalCodes">targetPostalCodes:</label>
        <input id="targetPostalCodes" class="targetPostalCodes" placeholder="BS1,SW1A"/>
        <label for="postalCode">postalCode:</label>
        <input id="postalCode" class="postalCode" placeholder="B1"/>
        <label for="lat">lat:</label>
        <input id="lat" class="lat" placeholder=""/>
        <label for="lng">lng:</label>
        <input id="lng" class="lng" placeholder=""/>
        <label for="orderBy">orderBy:</label>
        <input id="orderBy" class="orderBy" placeholder=""/>
        <label for="maxResults">maxResults:</label>
        <input id="maxResults" class="maxResults" placeholder=""/>
        <label for="algorithm">algorithm:</label>
        <input id="algorithm" class="algorithm" placeholder="straight"/>
      </div>
      <div>
        <span style="color: red" class="message"></span>
      </div>
      <div>
        <button type="submit">Submit</button>
      </div>
      <br />
      <div>Response</div>
      <br />
      <div>Full Response</div>
      <pre class="jsonResponse"></pre>
    </form>
  2. Add interaction

    Add the following JavaScript code in a separate pro6pp_great-britain_locator.js file. The IDs and Class names of the HTML elements should match with the ones specified in this JavaScript file in order to get the correct results.

    pro6pp_great-britain_locator.js
    document.addEventListener("DOMContentLoaded", function() {
        const pro6ppAuthKey = "AUTH_KEY"; // Replace with your actual authorization key
    
        let messageSpan = document.querySelector(".message");
        let jsonResponseSpan = document.querySelector(".jsonResponse");
        const BASE_URL = "https://api.pro6pp.nl/v2";
    
        function fetchAddress(authKey) {
            const queryParams = {
                targetPostalCodes: document.getElementById("targetPostalCodes").value,
                authKey: authKey
            };
            const optionalQueryParams = [
                "postalCode",
                "lat",
                "lng",
                "orderBy",
                "maxResults",
                "algorithm",
            ];
            for (const name of optionalQueryParams) {
                const value = document.getElementById(name).value;
                if (value !== "") {
                    queryParams[name] = value;
                }
            }
    
            let encodedUrl = new URL(`${BASE_URL}/locator/gb`);
            encodedUrl.search = new URLSearchParams(queryParams);
    
            fetch(encodedUrl)
                .then(async (response) => {
                    const data = await response.json();
                    if (data) {
                        messageSpan.textContent = "";
                        jsonResponseSpan.textContent = JSON.stringify(data, null, 2);
                    }
                })
                .catch((error) => {
                    console.error("Error fetching: ", error);
                    messageSpan.textContent = error.message;
                });
        }
    
        const form = document.getElementById("form");
        form.onsubmit = function (event) {
            event.preventDefault();
            fetchAddress(pro6ppAuthKey);
        }
    });
  3. Make it work

    Link the JavaScript file inside the pro6pp_great-britain_locator.html right before closing the </body> tag.

    pro6pp_great-britain_locator.html
      ...
      <script src="pro6pp_great-britain_locator.js"></script>
     </body>
    </html>

    To access the Pro6PP web service, you need to request your personal authorization key. This key is emailed to you right after signing up. Replace the above placeholder AUTH_KEY with your personal authorization key.

    If you don’t have an account yet, sign up for a free 2-month trial. After creating your account, go to your Subscription details and copy your AUTH_KEY. You’ll need this key to authenticate your requests.

  4. See it in action

    Once you’ve completed the previous steps, it’s time to run the form locally in your browser. You should now have two files in the same folder on your computer:

    • pro6pp_great-britain_locator.html - the HTML page with the form.
    • pro6pp_great-britain_locator.js - the JavaScript file that handles the interaction.

    You can now open the HTML file in your browser by simply double-clicking it in your file explorer (e.g., Finder on macOS or File Explorer on Windows). Alternatively, you can open it manually in the browser using the full file:/// path. For example:

    Example file paths
    file:///C:/Users/YourName/Documents/pro6pp_great-britain_locator.html
    file:///Users/yourname/Desktop/pro6pp_great-britain_locator.html

    Once the page opens, start typing in the form fields and hit Submit to see the API response displayed in the “Full Response” section.