Code lists

A code list is a controlled set of allowable values that can be used within a query parameter or included in the response. This page show the code lists used within OS Places API.

Logical status code

Logical status of an address record as given by the local custodian. These attributes show whether the address is currently live, provisional or historic.

Logical Status Code	Logical Status Description
1	Approved address
6	Provisional address
8	Historic address

LPI logical status code

Logical Status Code	Logical Status Description
1	Approved address
3	Alternate address
6	Provisional address
8	Historic address

Country code

Code representing the geographical territory that the Address is located within, where a geographical territory represents either a devolved country or an island nation.

Country Code	Country Code Description
E	This record is within England
W	This record is within Wales
S	This record is within Scotland
N	This record is within Northern Ireland
L	This record is within Channel Islands
M	This record is within Isle of Man
J	This record is not assigned to a country as it falls outside of the land boundaries used

Classification code

An alphanumeric code used to classify the object using the AddressBase Classification Scheme.

BLPU state code

BLPU State Code	BLPU State Description
1	Under construction
2	In use
3	Unoccupied / Vacant / Derelict
4	No longer existing
6	Planning permission granted

RPC code

RPC Code	RPC Description
1	Central Internal Position
2	General Internal Position
3	Transitional Position
4	Street Location
5	Postcode Unit Position
9	Low accuracy – marked for priority review

Match scores and descriptions

Every address record returned will have MATCH and MATCH_DESCRIPTION attributes which can help you select the most appropriate one:

Match Score	Match Description
1.0	Exact
0.8 - 0.9	Good
0.7	Partial
0.6 and under	No Match

Example searches and their match scores

If an exact match isn’t found, then the results will be returned in an order based on their match scores. The match score can help you select the most appropriate address record. These example searches show the affect that different search terms and the use of different parameters can have on the match score of the top result returned:

Query	Match Score
query=ORDNANCE SURVEY, 4, ADANAC DRIVE, NURSLING, SOUTHAMPTON, SO16 0AS	"MATCH": 1.0, "MATCH_DESCRIPTION": "EXACT"
query=ORDNANCE SURVEY, ADANAC DRIVE, SOUTHAMPTON, SO16 0AS	"MATCH": 0.9, "MATCH_DESCRIPTION": "GOOD"
query=ORDNANCE SURVEY, ADANAC DRIVE, SO16 0AS&matchprecision=	"MATCH": 0.89, "MATCH_DESCRIPTION": "GOOD"
query=ORDNANCE SURVEY, ADANAC DRIVE, SO16 0AS&matchprecision=2&minmatch=0.9	No result

Tips to improve your match results

• Match results can be greatly improved by including commas to separate your search terms, for example, ‘Ordnance Survey, 4, Adanac Drive, Nursling, Southampton, SO16 0AS’.

• Make sure the address elements in your search are in the correct order.

• Make sure you provide enough information when searching for an address. Remember that postcodes can cover up to 99 properties; therefore, including a street name and building name / number will narrow down the search results.

• Don't over complicate your search with unnecessary elements, for example, ‘Room 301, Level 3, Organisation Name, Building Name, Street, Postcode’ includes information that is not held in the database (Room 301, Level 3) and could be removed from the search to help improve the results.

• Remember that organisations move or change names; therefore, if your results are not satisfactory, consider only searching on Building Name, Street and Postcode instead.

• Make sure that postcodes in your search are current as they can be terminated. One option for this is to use the Office for National Statistics Postcode Directory (ONSPD). ONSPD identifies out-of-date postcodes with the date of termination (doterm attribute), where, when populated, provides the date when the postcode was terminated.

• Use the Country code filter parameter to limit results from specific countries only.