addressbase

This endpoint provides you with access to either AddressBase Core or AddressBase Premium, and returns one or more property records that match a given postcode or part of an address.

For AddressBase Premium, only property records with an associated Delivery Point Address (DPA) record that matches the search term will be returned. A DPA record is one that has been matched by Ordnance Survey against a Royal Mail PAF address; not every property record will have an associated DPA record.

Your API key determines whether you access AddressBase Core or AddressBase Premium.

AddressBase: Enable access on your API key using the Features page or by contacting us.

Request URL

https://ws.postcoder.com/pcw/{apikey}/addressbase/{searchterm}

Path parameters

Parameter	Description	Example
`apikey`	Your API key	`PCW45-12345-12345-1234X`
`searchterm`	The URL-encoded postcode or part of an address that you wish to look up	`nr1%201ne`

Querystring parameters

Parameter	Description	Example
`format`	Sets the format of the response, xml or json (default unless "application/xml" header is detected)	`format=json`
`identifier`	Specifies your own meaningful identifier for the request such as "websiteA" or "client123"; you can view usage for each identifier on the Identifier Usage page, which may be helpful when using your API key across multiple websites, apps or clients	`identifier=websiteA`
`lines`	Sets the number of address lines (1-9) to include in the response so you can mirror the layout of your existing address form; use include and exclude below to further customise the address lines	`lines=3`
`include`	Specifies the extra address fields to include within the address lines using a comma-delimited list, supported values: posttown, postcode	`include=posttown,postcode`
`exclude`	Specifies the address fields to exclude within the address lines using a comma-delimited list, supported values: pobox, organisation, departmentname, buildingname, subbuildingname, number, premise, dependentstreet, street, doubledependentlocality, dependentlocality	`exclude=organisation`
`postcodeonly`	Limits the request to a postcode-only search rather than matching the search term on other parts of an address, true or false (default)	`postcodeonly=true`
`callback`	Specifies the name of your JSONP callback function	`callback=jsoncallback`
`page`	Specifies the index of the page of results to return; the first page is returned by default and has an index of 0, the second page has an index of 1 and so on; see pagination for more info	`page=1`

Example request and response

Return property records with an associated Delivery Point Address (DPA) record that matches a postcode of NR1 4DH and include up to 3 address lines in the response:

https://ws.postcoder.com/pcw/PCW45-12345-12345-1234X/addressbase/nr1%204dh?format=json&lines=3

[
	...
	...
	{
		"addressline1": "The Dean & Chapter of Norwich Cathedral",
		"addressline2": "Chapter Office",
		"addressline3": "65 The Close",
		"summaryline": "The Dean & Chapter of Norwich Cathedral, Chapter Office, 65 The Close, Norwich, NR1 4DH",
		"organisation": "The Dean & Chapter of Norwich Cathedral",
		"subbuildingname": "Chapter Office",
		"number": "65",
		"uniquedeliverypointreferencenumber": "17308537",
		"premise": "Chapter Office, 65",
		"street": "The Close",
		"posttown": "Norwich",
		"postcode": "NR1 4DH",
		"latitude": "52.6308744",
		"longitude": "1.3009883",
		"grideasting": "623485.0",
		"gridnorthing": "308793.0",
		"uprn": "200004353841",
		"usrn": "28920601"
	},
	...
	...
]

Response fields

The following fields are returned in the response for AddressBase Core:

Field	Description	Example
`summaryline`	The address given in a single field separated by commas. Where matched against PAF this is a postal address	The Dean & Chapter of Norwich Cathedral, Chapter Office, 65 The Close, Norwich, NR1 4DH
`addressline1`	The first address line, where the total number of address lines is defined by the `lines` querystring parameter	The Dean & Chapter of Norwich Cathedral
`addressline2`	The second address line	Chapter Office
`addressline3`	The third address line	65 The Close
`addressline4`	The fourth address line
`addressline5`	The fifth address line
`addressline6`	The sixth address line
`addressline7`	The seventh address line
`addressline8`	The eighth address line
`addressline9`	The ninth address line
`organisation`	Organisation name. Source: Royal Mail where matched to a PAF delivery point where there is a deliverypointaddress record shown in AddressBase Premium or council records	The Dean & Chapter of Norwich Cathedral
`departmentname`	Where there is a distinct delivery point for receipt of mail for a department, the department name is indicated here. Source: Royal Mail where matched to a PAF delivery point where there is a deliverypointaddress record shown in AddressBase Premium or council records
`pobox`	Where linked to a PAF PO Box holder, this is the PO Box number. Source: Royal Mail where matched to a PAF delivery point where there is a deliverypointaddress record shown in AddressBase Premium or council records
`subbuildingname`	Sub-building name – usually a unit number or flat number. Source: Royal Mail where matched to a PAF delivery point where there is a deliverypointaddress record shown in AddressBase Premium or council records	Chapter Office
`buildingname`	Name of the building. For instance Nelson House. May or may not be further sub-divided. Often contains what Royal Mail would class as a Dependent Street. Source: Royal Mail where matched to a PAF delivery point where there is a deliverypointaddress record shown in AddressBase Premium or council records
`number`	The street number. Note that this may be alpha numeric. E.g. 1A. Source: Royal Mail where matched to a PAF delivery point where there is a deliverypointaddress record shown in AddressBase Premium or council records	65
`uniquedeliverypointreferencenumber`	Royal Mail's unique identifier for a Delivery Point (i.e. where postal delivery staff go to deliver mail). Assigned by Royal Mail and only available where an address record has been matched against PAF. Provides a unique identifier and designed to be unique over the life time of a delivery point	17308537
`premise`	A concatenation of the Department, PO Box, Sub-building Name, Building Name and Number (in that order). Useful if you have a single field in your database for storing the premise	Chapter Office, 65
`dependentstreet`	A street that needs another one for access. For example a cul-de-sac or a named parade of shops on a main road
`street`	The main street on which a property is situated. Commonly seems to be a main road especially in rural and remote settings. Source: Royal Mail where matched to a PAF delivery point where there is a deliverypointaddress record shown in AddressBase Premium or council records	The Close
`doubledependentlocality`	This is a smaller industrial estate or sub-division of a town or village. The data in this field comes from Royal Mail if the record has been matched to a delivery point but the equivalent data from council records goes into Dependentlocality
`dependentlocality`	This is analogous to Royal Mail's Double Dependent Locality and is generally representative of retail parks or industrial estates. Source: Council records or, if PAF matched, Royal Mail
`townname`	This is analogous to Royal Mail's Dependent Locality and represents a suburb or small town. Source: Royal Mail where matched to a PAF delivery point where there is a deliverypointaddress record shown in AddressBase Premium or council records
`posttown`	Where an address record has been matched against PAF, this is the post town responsible for mail sorting. Source: Royal Mail where matched to a PAF delivery point where there is a deliverypointaddress record shown in AddressBase Premium or council records	Norwich
`postcode`	This is the Postcode assigned by Royal Mail	NR1 4DH
`deliverypointsuffix`	The Delivery Point Suffix used by Royal Mail. This, along with a Postcode, provides a unique identifier for a delivery point at a point in time. Source: Royal Mail
`latitude`	This is the latitude on the ETRS89 projection. See rpc	52.6308744
`longitude`	This is the longitude on the ETRS89 projection. See rpc	1.3009883
`grideasting`	The Easting on Ordnance Survey's British National Grid. The units are in metres to 2 decimal places. See rpc	623485.00
`gridnorthing`	The Northing on Ordnance Survey's British National Grid. The units are in metres to 2 decimal places. See rpc	308793.00
`uprn`	The Unique Property Reference Number – the primary key field for AddressBase data. Assigned by GeoPlace or Ordnance Survey	200004353841
`parentuprn`	Where a particular property is part of another one (for example a flat in a block of flats or a unit on a business park) the owning property's UPRN is indicated here. Please note that this is not the same as Royal Mail's multiple residence indicator for postal purposes but is a good indicator that this is not a stand-alone property
`usrn`	The Unique Street Reference Number – every street under council control has its own unique identifier and this is it	28920601
`changecode`	Indicates how this record was last amended on the national hub. AddressBase Core only
`toid`	The topographical identifier which associates this record with OS MasterMap. AddressBase Core only
`classificationcode`	Describes the classification of the property according to council records	CO01
`rpc`	Tells you how accurate the coordinates are. For safety critical applications this may be a particularly important field: 1 – Central Internal Position – The address is contained within an OS MasterMap Topography Later building and within 2.5m of its calculated centre. Or the coordinates represent the best possible position based on the nature of the premises 2- General Internal Position – The address is contained within an OS MasterMap Topography Later building but is more than 2.5m away from its calculated centre. Or the seed is in an internal position based on the nature of the premises 3 – Transitional Position – The address has been changed from Under Development to Live within the last 6 months. It has been captured to a high level of positional accuracy but pending large scale mapping updates still may be moved 4 – Street Location – The address is plotted in accordance with the declared street start and end coordinates 5 – Postcode Unit position – The address has been captured to Postcode Unit level and will be updated when more information becomes available. It is likely that every property on the Postcode will be sharing these same coordinates 9 – Low Accuracy – The address has been captured to a lower level of accuracy and will be updated as a priority over the coming months	1
`gsscode`	Provided by the Office for National Statistics and used for official records. Codes are structured: the first three characters are an Entity Code and the remaining 6 characters are the particular instance. Entity Codes are: E06 (Unitary Authority); E07 (Local Authority District Council); E08 (Metropolitan Borough Council); and E09 (London Borough)
`lastupdatedate`	The date this record was last updated
`morevalues`	Set to true when there is another page of results beyond the current page; see pagination for more info	true
`nextpage`	The index of the next page of results; see pagination for more info	1
`totalresults`	The total number of results found; see pagination for more info	180

Pagination

When a request returns many addresses, Postcoder may paginate the response across multiple pages. The first page is returned by default and has an index of 0.

If another page is available, the last address on the current page will include two extra fields: morevalues (indicates another page is available when "true") and nextpage (provides the index of the next page).

[
    ...
    ...
    {
        // Last address on current page
        ...
        ...
        "posttown": "Norwich",
        "county": "Norfolk",
        "postcode": "NR1 1NE",
        "morevalues": "true",
        "nextpage": "1",
        "totalresults": "180"
    }
]

You can retrieve the next page by setting the page querystring parameter to the index of the next page. In the scenario above, you could do this by adding ?page=1 to your request.

Postcoder will truncate large responses to 60 pages; this limit may change from time to time.

Integration advice

URL encode all special characters (including /) in your request parameters with %xx encoding
Verify your request was successful by checking for an HTTP status code of 200; see all HTTP status codes with descriptions
When using your API key across multiple websites, apps or clients, set the identifier querystring parameter to a meaningful value such as "websiteA" or "client123"; you'll then be able to view these identifiers and the number of requests made by each one on the Identifier Usage page
Treat all response fields as optional
Use these fields on your UK address form: addressline1, addressline2, addressline3, posttown, postcode (county is no longer required in UK addresses)

Credit cost

Each request costs 3.5 credits.

Buy a credit pack or set up a monthly plan to use with all Postcoder endpoints.