# Postcode

{% hint style="warning" %}

### API test authentication

The Open API block allows you to test OS APIs directly from the page with example data and parameters. To use this feature, you will need to add your API Key or OAuth2 token to the authentication field.

For help generating an API Key or OAuth2 token, please see the [Getting started with an API project](https://docs.os.uk/os-apis/core-concepts/getting-started-with-an-api-project) or [OAuth2 documentation](https://docs.os.uk/os-apis/accessing-os-apis/oauth-2-api).
{% endhint %}

## GET /postcode

> Returns matched addresses based on a property's postcode.

```json
{"openapi":"3.0.1","info":{"title":"OS Places API","version":"v1.0"},"tags":[{"name":"Postcode","description":"A search based on a property’s postcode"}],"servers":[{"url":"https://api.os.uk/search/places/v1"}],"security":[{"api-key":[],"api-key-header":[],"oauth2":[]}],"components":{"securitySchemes":{"api-key":{"type":"apiKey","name":"key","in":"query"}},"schemas":{"SearchResult":{"type":"object","properties":{"header":{"type":"object","properties":{"uri":{"type":"string"},"query":{"type":"string"},"offset":{"type":"integer"},"totalresults":{"type":"integer"},"format":{"type":"string"},"dataset":{"type":"string"},"lr":{"type":"string"},"maxresults":{"type":"integer"},"matchprecision":{"type":"integer"},"epoch":{"type":"string"},"lastupdate":{"type":"string"},"output_srs":{"type":"string"}},"required":["uri","query","offset","totalresults","format","dataset","lr","maxresults","matchprecision","epoch","lastupdate","output_srs"]},"results":{"type":"array","items":{"type":"object","properties":{"DPA":{"$ref":"#/components/schemas/DPA"},"LPI":{"$ref":"#/components/schemas/LPI"}}}}}},"DPA":{"type":"object","properties":{"UPRN":{"type":"string"},"UDPRN":{"type":"string"},"ADDRESS":{"type":"string"},"ORGANISATION_NAME":{"type":"string"},"DEPARTMENT_NAME":{"type":"string"},"SUB_BUILDING_NAME":{"type":"string"},"BUILDING_NAME":{"type":"string"},"BUILDING_NUMBER":{"type":"string"},"DEPENDENT_THOROUGHFARE_NAME":{"type":"string"},"THOROUGHFARE_NAME":{"type":"string"},"DOUBLE_DEPENDENT_LOCALITY":{"type":"string"},"DEPENDENT_LOCALITY":{"type":"string"},"POST_TOWN":{"type":"string"},"POSTCODE":{"type":"string"},"RPC":{"type":"string"},"X_COORDINATE":{"type":"number"},"Y_COORDINATE":{"type":"number"},"LNG":{"type":"number"},"LAT":{"type":"number"},"STATUS":{"type":"string"},"LOGICAL_STATUS_CODE":{"type":"string"},"CLASSIFICATION_CODE":{"type":"string"},"CLASSIFICATION_CODE_DESCRIPTION":{"type":"string"},"LOCAL_CUSTODIAN_CODE":{"type":"integer"},"LOCAL_CUSTODIAN_CODE_DESCRIPTION":{"type":"string"},"COUNTRY_CODE":{"type":"string"},"COUNTRY_CODE_DESCRIPTION":{"type":"string"},"POSTAL_ADDRESS_CODE":{"type":"string"},"POSTAL_ADDRESS_CODE_DESCRIPTION":{"type":"string"},"BLPU_STATE_CODE":{"type":"string"},"BLPU_STATE_CODE_DESCRIPTION":{"type":"string"},"TOPOGRAPHY_LAYER_TOID":{"type":"string"},"WARD_CODE":{"type":"string"},"PARISH_CODE":{"type":"string"},"PARENT_UPRN":{"type":"string"},"LAST_UPDATE_DATE":{"type":"string"},"ENTRY_DATE":{"type":"string"},"LEGAL_NAME":{"type":"string"},"BLPU_STATE_DATE":{"type":"string"},"LANGUAGE":{"type":"string"},"MATCH":{"type":"number"},"MATCH_DESCRIPTION":{"type":"string"},"DELIVERY_POINT_SUFFIX":{"type":"string"}}},"LPI":{"type":"object","properties":{"UPRN":{"type":"string"},"ADDRESS":{"type":"string"},"USRN":{"type":"string"},"LPI_KEY":{"type":"string"},"ORGANISATION":{"type":"string"},"SAO_START_NUMBER":{"type":"string"},"SAO_START_SUFFIX":{"type":"string"},"SAO_END_NUMBER":{"type":"string"},"SAO_END_SUFFIX":{"type":"string"},"SAO_TEXT":{"type":"string"},"PAO_START_NUMBER":{"type":"string"},"PAO_START_SUFFIX":{"type":"string"},"PAO_END_NUMBER":{"type":"string"},"PAO_END_SUFFIX":{"type":"string"},"PAO_TEXT":{"type":"string"},"STREET_DESCRIPTION":{"type":"string"},"LOCALITY_NAME":{"type":"string"},"TOWN_NAME":{"type":"string"},"ADMINISTRATIVE_AREA":{"type":"string"},"AREA_NAME":{"type":"string"},"POSTCODE_LOCATOR":{"type":"string"},"RPC":{"type":"string"},"X_COORDINATE":{"type":"number"},"Y_COORDINATE":{"type":"number"},"LNG":{"type":"number"},"LAT":{"type":"number"},"STATUS":{"type":"string"},"LOGICAL_STATUS_CODE":{"type":"string"},"CLASSIFICATION_CODE":{"type":"string"},"CLASSIFICATION_CODE_DESCRIPTION":{"type":"string"},"LOCAL_CUSTODIAN_CODE":{"type":"integer"},"LOCAL_CUSTODIAN_CODE_DESCRIPTION":{"type":"string"},"COUNTRY_CODE":{"type":"string"},"COUNTRY_CODE_DESCRIPTION":{"type":"string"},"POSTAL_ADDRESS_CODE":{"type":"string"},"POSTAL_ADDRESS_CODE_DESCRIPTION":{"type":"string"},"BLPU_STATE_CODE":{"type":"string"},"BLPU_STATE_CODE_DESCRIPTION":{"type":"string"},"TOPOGRAPHY_LAYER_TOID":{"type":"string"},"WARD_CODE":{"type":"string"},"PARISH_CODE":{"type":"string"},"PARENT_UPRN":{"type":"string"},"LAST_UPDATE_DATE":{"type":"string"},"ENTRY_DATE":{"type":"string"},"LEGAL_NAME":{"type":"string"},"BLPU_STATE_DATE":{"type":"string"},"STREET_STATE_CODE":{"type":"string"},"STREET_STATE_CODE_DESCRIPTION":{"type":"string"},"STREET_CLASSIFICATION_CODE":{"type":"string"},"STREET_CLASSIFICATION_CODE_DESCRIPTION":{"type":"string"},"LPI_LOGICAL_STATUS_CODE":{"type":"string"},"LPI_LOGICAL_STATUS_CODE_DESCRIPTION":{"type":"string"},"LANGUAGE":{"type":"string"},"MATCH":{"type":"number"},"MATCH_DESCRIPTION":{"type":"string"}}}}},"paths":{"/postcode":{"get":{"tags":["Postcode"],"summary":"Returns matched addresses based on a property's postcode.","operationId":"getPostcode","parameters":[{"name":"postcode","in":"query","description":"The postcode search parameter.","required":true,"schema":{"type":"string"}},{"name":"format","in":"query","description":"The format the response will be returned in. Default: JSON.","required":false,"schema":{"type":"string","default":"JSON","enum":["JSON","XML"]}},{"name":"maxresults","in":"query","description":"The maximum number of results to return. Default: 100.","required":false,"schema":{"type":"integer","default":"100","minimum":1,"maximum":100}},{"name":"offset","in":"query","description":"Offset the list of returned results by this amount.","required":false,"schema":{"type":"integer","default":"0"}},{"name":"dataset","in":"query","description":"The dataset to return. Multiple values can be sent, separated by a comma. Default: DPA.","required":false,"schema":{"type":"string","default":"DPA","enum":["DPA","LPI"]}},{"name":"lr","in":"query","description":"Which language of addresses to return. Default: EN, CY.","required":false,"schema":{"type":"string","enum":["EN","CY"]}},{"name":"output_srs","in":"query","description":"The intended output spatial reference system. Default: EPSG:27700","required":false,"schema":{"type":"string","default":"EPSG:27700","enum":["BNG","EPSG:27700","WGS84","EPSG:4326","EPSG:3857","EPSG:4258"]}},{"name":"fq","in":"query","description":"Filter for classification code, logical status code, LPI logical status code and/or country code. Filtering for classification code will accept wildcard ( * ) searches. Multiple searches can be done by separating the codes with a space. Multiple filters can be used together by including the parameter multiple times","required":false,"schema":{"type":"array","items":{"type":"string"}}}],"responses":{"200":{"description":"Retrieves matched addresses","content":{"application/json":{"schema":{"$ref":"#/components/schemas/SearchResult"}},"application/xml":{"schema":{"$ref":"#/components/schemas/SearchResult"}}}}}}}}}
```


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.os.uk/os-apis/accessing-os-apis/os-places-api/technical-specification/postcode.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.