Doaa Kurdi



Address Autocomplete

A tool to extract address suggestions for a complete or partial address. For more information, view our Address Finder.

Alias Data

Alias data is information the public choose to use when addressing mail, but which isn’t actually required for delivery purposes.

Allowed URLs

A list of website addresses that can perform lookups using your API Key.


API stands for Application Programming Interface. It is a set of tools designed to create applications that access data of an operating system, application, or other service.

Closed User Group

A Closed User Group is

“ an End User’s network of businesses comprising that End User and not less than 10 Business Partners all of a single type.” ¹


A county is a subnational division of the United Kingdom, used for the purposes of administrative or geographical demarcation.

Data Cleansing

Data cleansing is a solution to remove duplicates, organise data in a consistent format and correct inaccurate data. The extraction of PAF Data or any part of it for the generation of new address records in a new or existing database.

Delivery Point

The letterbox where the mail is delivered.

Delivery Point Suffix

A Delivery Point Suffix is a digit followed by a letter, which is used to identify mailboxes in the UK.

Dependent Street

A Dependent Street is included in an address when the Delivery Point is not on the main street.

Dependent Thoroughfare

Distinguishes a premise when a thoroughfare appears more than once in a post town.

Dependent Locality

Distinguishes a premise when an address thoroughfare appears more than once in the same post town.

End User

An End User is a single legal entity entering into a PAF®, Multiple Residence™ or Not Yet Built™ licence agreement. Find out what classifies an End User.

Full/Part NYB

All elements recorded in the Not Yet Built Dataset. View our list of full/part NYB components.

Full/Part PAF

All elements recorded in PAF Data. See our list of full/part PAF components.

Fuzzy matching

A smart search functionality to correct typos or spelling mistakes. See more features on our address finder page.


Taking an address and returning a latitude/longitude location.

Internal User

Any staff member in an organisation authorised to use addressing data. Read more on End Users on our internal user guide.


An End User of PAF data licensed by a Sublicensing Key. For more information, please visit our Sublicensing page.

Licensee Key

A type of API Key that an individual Licensee can use to access PAF data

Multiple Residence

The Multiple Residence dataset identifies and verifies premises where households share the same letter box and provides a detailed address structure for these properties. Read more in our Multiple Residence guide.

Not Yet Built

The Not Yet Built dataset is an additional database from Royal Mail that lists properties currently in planning or under construction. Read more in our Not Yet Built guide.

Organisation Use

Available solutions to cover unlimited users. Contact us for high volume usage.

PAF Data

Royal Mail’s Postcode Address File (PAF) is a database containing more than 30 million postal delivery addresses and 1.8 million Postcodes. Read more on PAF.


Combination of alphanumeric characters used as part of a postal address. Every property in the UK has a postcode assigned to it. Learn how UK postcodes are formatted.

Postcode Area

Postcode Area refers to geographic areas defined by the first or first and second alphabetic characters of the postcode.

Postcode Lookup

A tool to search UK addresses from a postcode. View and try our Postcode Lookup demo.

Post Town

Also known as the Locality. However, the post town represents the postal delivery locality and not necessarily the geographic locality.

Service Level Agreement (SLA)

An agreement between a vendor and a customer outlining the services expected, how it is measured and the remedies and penalties is the agreed service levels are not met.


A product of service which benefits from or includes PAF data. Find out more about our solutions and how we can help.


A sub-building is known as a sub-premise, such as an apartment, flat, or suite.

Sublicensing Key

A type of API Key that can additional create Licensees Keys.


A Thoroughfare is known as the street or road.

Unique Delivery Reference Number (UDPRN)

A unique code used to identify a delivery point (i.e. premise) in PAF.

Unique Property Reference Number (UPRN)

A unique identifier for a UK addressable location, provided by Ordnance Survey.

Unique Street Reference Number (USRN)

A unique identifier for every street in Great Britain.


A User is anyone authorised by an End User to use a Solution.

Website Use

The use of PAF data to capture or verify addresses on webpages, mobile applications or landing pages.

¹ Glossary of Licensing Terms. (n.d.). Retrieved from