OS MasterMap^® Address Layer 2 ID X-Ref Table

There are so many different types of address being used in OS MasterMap Address Layer 2 that it has so far proved impossible to come up with a single, definitive specification for an address that satisfies all requirements.

Until such a definitive address exists, the ID cross-reference (X-ref) table will serve as a mechanism to allow the relationships between the different addresses created by organisations to be linked to each other so the equivalent address from a different organisation or set of organisations can be identified. This is one of the mechanisms to help establish the principles of DNF.

In the current release the ID X-ref table contains cross references between OS MasterMap Address Layer 2 features and the following datasets:

• The Royal Mail^® Postcode Address File (PAF^®), which provides the postally addressable properties;
• The new Royal Mail Multi-residence (MR) dataset, which provides households within buildings not normally accessible to the postal delivery person; and
• The Valuation Office Agency references for properties attracting either council tax or non-domestic rates.

There are three principles to be aware of when using the ID X-ref table:

• The Valuation Office Agency UARNs (unique address reference numbers) will only be present in England and Wales as the Valuation Office Agency only has jurisdiction for these two countries.
• There will be an element of work-in-progress; that is, some objects that have not yet been successfully correlated in each supply.
• There will be some objects that will never be correlated since they are unique to the particular source data provider.

The complete list of attributes contained within the table is as follows:

• Ordnance Survey Address TOID
• Ordnance Survey OSAPR
• Royal Mail UDPRN
• Royal Mail UMRRN
• Royal Mail Address Key
• Royal Mail Organisation Key
• Valuation Office Agency Council Tax UARN
• Valuation Office Agency Non-domestic Rates UARN 
• Ordnance Survey Address Version

The ID X-ref table is updated at the same time a new OS MasterMap Address product version is released.  This ensures that the same versions and instances of the features that are delivered within the OS MasterMap Layers are used in the table. This is to prevent the table's information being out of synchronisation with the actual features. The table is not automatically supplied; a customer must specify that it is required when an order is placed.

The ID X-ref table is not cut to a customer’s particular order but is supplied as a full GB set in CSV format.

If you would like to receive a free ID X-ref table, then please read the agreement for the supply of ID X-ref table relating to OS MasterMap Address Layer 2 PDF (114 Kb) and send an email to our Commercial team, detailing your name, address, telephone number, email address and company name using the contact details at the end of the document.

_{PAF and Royal Mail are registered trademarks of Royal Mail Group plc.}