Unique Identifier

Unique ID’s in the UK (UPRN/UDPRN)

Discover UK's Unique Address Identifiers (UPRN/UDPRN) tracing properties, addresses & boundaries for precise location insights.

The United Kingdom is somewhat of a leader in unique identifiers. Relative for their size, there are multiple identifiers that are available. We will look at the benefits and differences for the two most popular ones, which are Royal Mail's UDPRN and Ordnance Survey's UPRN.


These identifiers are created and maintained by reputable and stable organizations and well used. That means that everyone who uses these values agrees on exactly what they mean. You can easily trace a number back to a property parcel, an address, or boundary shape. UK Government entities often use these values and this is an easy way to interface with these entities.


Close look at UPRN/UDPRN

UPRN (Unique Property Reference Number)

UPRN is a 12-digit unique numeric identifier for every addressable location in Great Britain. Essential for bringing property and address information together.

These keys are assigned to approximately 40 million addressable locations, which may be any kind of building, residential or commercial. It may also be an object that might not have a ‘postal’ address – such as a bus shelter or electricity sub-station. This will enable you to analyze and visualize using the accurate location.

UPRN are primarily allocated by Local Authorities, under their legal duty to maintain this information. Thus, you can be confident you are accessing an authoritative source of these identifiers.

UDPRN (Unique Delivery Point Reference Number)

UDPRN is a numeric 8-digit code used by the Royal Mail to identify postal addresses in the UK. Each postal address within the Royal Mail PAF® database has a unique UDPRN. The UDPRN for a Delivery Point remains fixed regardless of any changes in the address itself (e.g. through corrections, company name changes or postcode modifications). UDPRNs are not re-assigned if a Delivery Point is deleted from PAF® but can be reactivated if the original Delivery Point is added back into PAF®.

UDPRN is useful for organizations in sectors like shipment, logistics, delivery, anyone who needs to identify a delivery point correctly the first time, every time.


Between these two identifiers, which one you use is really based on which data your organization is more interested in, RoyalMail vs Ordnance Survey. You can also simply use both. Melissa's Global Address product has both UPRN and UDPRN as available outputs for UK addresses.

Melissa Address Keys

Here at Melissa, we have our own version of unique identifiers. We will call these keys MAK for short. These are 10-digit unique identifier that are guaranteed to be unique for all addresses. The main difference between UPRN/UDPRN and MAK numbers are that the latter apply not only to the UK but to all major countries like Canada, United States, Germany, France, etc.

How to Choose a Solution

Find the right address solution for your business by requesting a demonstration today.

At Melissa, we’ve leveraged 38 years of address verification expertise to give you the best possible products. Learn more from our collection of Address Experts articles.

Similar posts

Get notified on new data quality features and insights

Be the first to know about new data quality and product features.