# Address Classifications ## Addressing Classification Levels The Addressing classification scheme provides varying levels of classification for addressable objects which are captured and maintained by the Local Authorities and Ordnance Survey. You can query the data to explore residential and commercial properties at the primary classification level. Or you can carry out a more specific query using the secondary and tertiary level classifications. However, there are only certain classification codes that extend to the quaternary classification level.

Table showing the four levels of classification

The level of classification varies across all addressable objects and across the different products.

Product	Primary	Secondary	Tertiary	Quaternary
AddressBase	Yes	No	No	No
AddressBase Core	Yes	Yes	No	No
AddressBase Plus	Yes	Yes	Yes	Yes
AddressBase Premium	Yes	Yes	Yes	Yes
OS NGD Address	Yes	Yes	Yes	Yes

The full list of classification codes can be found on the [OS website](https://www.ordnancesurvey.co.uk/documents/product-support/support/addressbase-product-classification-scheme.zip) ## Use Case - Health Centre CM02HC {% tabs %} {% tab title="AddressBase" %} AddressBase does not allow access to beyond primary level classifications. You can only query to identify Commercial classifications (C) ```sql Select addr.* from addressbase.addressbase addr Where addr.class = 'C' ``` This returns 1.3 million records nationally

AddressBase records for classification 'C'

{% endtab %} {% tab title="AddressBase Core" %} AddressBase Core does not allow access to beyond secondary level classifications. You can only query to identify Medical classifications (CM). ```sql Select addr.* from abcore.addressbasecore addr Where addr.class = 'CM' ``` This returns over 53,000 records nationally

AddressBase Core records for classification 'CM'

{% endtab %} {% tab title="AddressBase Plus" %} AddressBase Plus allows access to quaternary level classifications. You can query to identify Health Centre classifications (CM02HC). ```sql Select addr.* from abplus.addressbaseplus addr Where addr.class = 'CM02HC' ``` This returns approximately 3700 records nationally

AddressBase Plus records for classification 'CM02HC'

{% endtab %} {% tab title="AddressBase Premium" %} AddressBase Premium allows access to quaternary level classifications. You can query to identify Health Centre classifications (CM02HC). However, you will need to use the UPRN as a common key to join to additional attribution from other tables (e.g. geometry from the BLPU table). ```sql Select clas.*, blpu.geom from abpremium.classification clas Inner Join abpremium.blpu blpu on clas.uprn = blpu.uprn Where clas.classification_code = 'CM02HC' ``` This returns approximately 3700 records nationally

AddressBase Premium records for classification 'CM02HC'

{% endtab %} {% tab title="OS NGD Address" %} OS NGD Address allows access to quaternary level classifications for each of the address statuses. You can query to identify Health Centre classifications (CM02HC). This was carried out for built properties. ```sql Select builtaddress.* from osngd_add_gb.add_gb_builtaddress builtaddress Where builtaddress.classification_code = 'CM02HC' ``` This returns approximately 3700 records nationally

OS NGD Address records for classification 'CM02HC'

{% endtab %} {% endtabs %} *** ## Find out more [OS NGD Documentation](https://docs.os.uk/osngd) [OS Data Hub](https://osdatahub.os.uk/) [GitHub](https://github.com/OrdnanceSurvey/osngd-resources) [OS Select and Build](https://www.ordnancesurvey.co.uk/business-government/products/os-select-build) *** This content has been developed from what was originally a Lightning Talk PowerPoint slide set. These slides are available to PSGA members to view and download from the [PSGA members area of the OS website](https://auth.ordnancesurvey.co.uk/my.policy)