Bulk Reverse Geocode Postcodes

Translates multiple geographic coordinates (longitude/latitude) into postcodes in a single request. This endpoint returns the nearest postcodes for each set of coordinates provided.

POST https://api.postcodes.io/postcodes

Endpoint

POST https://api.postcodes.io/postcodes

Example Request

POST https://api.postcodes.io/postcodes HTTP/1.1
Content-Type: application/json

{
  "geolocations": [
    {
      "longitude": -3.15807731271522,
      "latitude": 51.4799900627036
    },
    {
      "longitude": -1.12935802905177,
      "latitude": 50.7186356978817,
      "radius": 500,
      "limit": 5
    }
  ]
}

Example Response

{
  "status": 200,
  "result": [
    {
      "query": {
        "longitude": -3.15807731271522,
        "latitude": 51.4799900627036
      },
      "result": [
        {
          "postcode": "CF24 2BT",
          "quality": 1,
          "eastings": 319675,
          "northings": 176305,
          "country": "Wales",
          "nhs_ha": "Cardiff and Vale University Health Board",
          "longitude": -3.158085,
          "latitude": 51.479977,
          "european_electoral_region": "Wales",
          "primary_care_trust": "Cardiff and Vale University Health Board",
          "region": null,
          "lsoa": "Cardiff 038D",
          "msoa": "Cardiff 038",
          "incode": "2BT",
          "outcode": "CF24",
          "parliamentary_constituency": "Cardiff South and Penarth",
          "parliamentary_constituency_2024": "Cardiff South and Penarth",
          "senedd_constituency": "Caerdydd Penarth",
          "senedd_constituency_no": 14,
          "admin_district": "Cardiff",
          "parish": "Splott",
          "admin_county": "(pseudo) Wales",
          "date_of_introduction": "199906",
          "date_of_termination": null,
          "index_of_multiple_deprivation": 12,
          "admin_ward": "Splott",
          "ced": null,
          "ccg": "Cardiff and Vale University",
          "nuts": "Cardiff",
          "pfa": "South Wales",
          "nhs_region": null,
          "ttwa": "Cardiff",
          "national_park": "Wales (non-National Park)",
          "bua": "Cardiff",
          "icb": "Wales",
          "cancer_alliance": null,
          "lsoa11": "Cardiff 038D",
          "msoa11": "Cardiff 038",
          "lsoa21": "Cardiff 038D",
          "msoa21": "Cardiff 038",
          "oa21": "W00009646",
          "ruc11": "(England/Wales) Urban city and town",
          "ruc21": "Urban: Nearer to a major town or city",
          "lep1": null,
          "lep2": null,
          "codes": {
            "admin_district": "W06000015",
            "admin_county": "W99999999",
            "admin_ward": "W05001295",
            "parish": "W04001005",
            "parliamentary_constituency": "W07000091",
            "parliamentary_constituency_2024": "W07000091",
            "ccg": "W11000029",
            "ccg_id": "7A4",
            "ced": "W99999999",
            "nuts": "TLL52",
            "lsoa": "W01001874",
            "msoa": "W02000404",
            "lau2": "W06000015",
            "pfa": "W15000003",
            "nhs_region": "W99999999",
            "ttwa": "W22000024",
            "national_park": "W31000001",
            "bua": "W45001208",
            "icb": "W99999999",
            "cancer_alliance": "W99999999",
            "lsoa11": "W01001874",
            "msoa11": "W02000404",
            "lsoa21": "W01001874",
            "msoa21": "W02000404",
            "oa21": "W00009646",
            "ruc11": "C1",
            "ruc21": "UN1",
            "lep1": "W99999999",
            "lep2": null
          },
          "distance": 1.5469903262881375
        }
        // Additional results omitted for brevity
      ]
    },
    {
      "query": {
        "longitude": -1.12935802905177,
        "latitude": 50.7186356978817,
        "radius": 500,
        "limit": 5
      },
      "result": [
        {
          "postcode": "PO33 1PS",
          "quality": 1,
          "eastings": 461564,
          "northings": 91388,
          "country": "England",
          "nhs_ha": "South Central",
          "longitude": -1.129272,
          "latitude": 50.718856,
          "distance": 25.234110225937016
          // Additional fields omitted for brevity
        }
        // Additional results omitted for brevity
      ]
    }
  ]
}

Request Parameters

This endpoint requires a JSON object containing an array of geolocation objects:

Parameter	Description	Required	Constraints
`geolocations`	Array of geolocation objects	Yes	Maximum 100 objects
`longitude`	Longitude coordinate	Yes	Valid longitude value
`latitude`	Latitude coordinate	Yes	Valid latitude value

You can include up to 100 geolocation objects in a single request.

Example JSON body:

{
  "geolocations": [
    {
      "longitude": -0.32824866,
      "latitude": 51.44344409
    },
    {
      "longitude": -0.20864309,
      "latitude": 51.42001847
    }
  ]
}

Optional Query Parameters

These parameters can be applied globally to all geolocations in the request:

Parameter	Description	Default	Constraints
`limit`	Maximum number of postcodes to return for each location	10	Must be less than 100
`radius`	Search radius in metres	100	Must be less than 2,000m
`widesearch`	When true, extends search radius up to 20km	false	Returns maximum of 10 results

Example with global parameters:

POST https://api.postcodes.io/postcodes?radius=200&limit=5

Optional Geolocation Object Parameters

These parameters can be specified for individual geolocation objects:

Parameter	Description	Default	Constraints
`limit`	Maximum number of postcodes to return for this location	10	Must be less than 100
`radius`	Search radius in metres for this location	100	Must be less than 2,000m
`widesearch`	When true, extends search radius up to 20km	false	Returns maximum of 10 results
`filter`	Comma-separated list of fields to return	All fields	e.g. `postcode,longitude,latitude`

Individual parameters override global parameters for the specific geolocation object.

Response Details

Each geolocation query returns an array of matching postcodes
Results are sorted by distance (nearest first)
Each result includes a distance field showing meters from the query point
If no postcodes are found within the radius, result will be an empty array
If a geolocation is invalid, result will be null

Endpoint​

Example Request​

Example Response​

Request Parameters​

Optional Query Parameters​

Optional Geolocation Object Parameters​

Response Details​