AddressBase Products September 2025 – Epoch 121

This release note provides information about the September 2025 (Epoch 121) release of the AddressBase products. These products were released to customers on 04 September 2025.

Record counts

Product	Full Supply Record Count	Change-Only Update Record Count
OS Open UPRN	41 270 485	N/A
AddressBase	30 780 777	190 178
AddressBase Plus	38 504 602	747 079
AddressBase Premium	See rows below	See rows below
Street	1 518 951	6 979
Street Descriptor	1 643 024	3 566
BLPU	41 318 791	497 400
Classification	45 127 550	186 102
LPI	46 609 084	196 818
Organisation	1 396 937	21 750
Delivery Point Address	30 893 176	81 996
Application Cross Ref.	199 960 916	1 028 132
Successor	0	0

• The Full Supply record counts are based on a Managed Great Britain Set (MGBS). If you have ordered your national coverage via the online ordering system using a polygon outline, then your counts may differ.

• Please note that Change-Only Updates (COUs) are not available for the OS Open UPRN product.

Product supply comparison

There is a difference in product counts between taking a national Managed Great Britain Set (MGBS) and a national Area of Interest (AOI). This is because the two supplies use different selection criteria. The differences are shown in the following table, allowing for you to validate your data holdings once you have loaded the latest release of AddressBase data.

The national AOI refers to the pre-selection GB polygon from our download store. Therefore, if you have drawn your own AOI, the count will vary.

If you are unsure of your supply type, please check this with your OS Relationship Manager.

Product	MGBS Full Count	National AOI Full Count	Difference
AddressBase	30 780 777	30 780 777	0
AddressBase Plus	38 504 602	38 504 577	25
AddressBase Premium	See rows below	See rows below	See rows below
Street	1 518 951	1 518 948	3
Street Descriptor	1 643 024	1 643 021	3
BLPU	41 318 791	41 318 761	30
Classification	45 127 550	45 127 518	22
LPI	46 609 084	46 609 053	31
Organisation	1 396 937	1 396 935	2
Delivery Point Address	30 893 176	30 893 176	0
Application Cross Ref.	199 960 916	199 960 885	31
Successor	0	0	0

It's important that COUs are processed with Deletes first, then Inserts and Updates. This is to ensure that updates are applied in the correct order. Further guidance on this can be found in 'Working with COU data' in the AddressBase Getting Started Guide.

Changed records

If you receive a Change-Only Update (COU) supply for your AddressBase product, you will receive Insert, Update and Delete records within the supplied file. The following tables detail the numbers of these records which can be expected in an MGBS supply, and also how many tiles are affected if you take your supply as Changed Chunks.

AddressBase

Change Type	Count
Inserts	49 044
Updates	131 238
Deletes	9 896
COU Populated Tile Count	5 351

AddressBase Plus

Change Type	Count
Inserts	67 012
Updates	665 372
Deletes	14 695
COU Populated Tile Count	7 259

AddressBase Premium

AddressBase Premium Table	Inserts	Updates	Deletes
Street	1 241	5 726	12
Street Descriptor	1 321	2 233	12
BLPU	50 956	443 794	2 650
Classification	65 969	95 869	24 264
LPI	68 758	123 806	4 254
Organisation	6 401	8 820	6 529
Delivery Point Address	49 531	22 842	9 623
Application Cross Ref.	227 695	720 867	79 570

Source data currency

The following information relates to the currency of the source data used in the creation of Epoch 121:

Data Source	Date
Royal Mail PAF	07 August 2025
National Land and Property Gazetteer	07 August 2025
One Scotland Gazetteer	14 July 2025
VOA Non-Domestic Rates	05 July 2025
VOA Council Tax	05 July 2025
OS MasterMap Topography Layer	10 July 2025
OS MasterMap Highways Network	07 August 2025
Code-Point with Polygons	01 July 2025
Boundary-Line	01 May 2025

Data issues

AddressBase

Details of live and resolved data issues for AddressBase will be communicated on the AddressBase Known Data Issues page. This page will provide details of their impacts and updates on the expected time frame for their resolution.

AddressBase Plus issues

Details of live and resolved data issues for AddressBase Plus will be communicated on the AddressBase Plus Known Data Issues page. This page will provide details of their impacts and updates on the expected time frame for their resolution.

AddressBase Premium

Details of live and resolved data issues for AddressBase Premium will be communicated on the AddressBase Premium Known Data Issues page. This page will provide details of their impacts and updates on the expected time frame for their resolution.

Improvements in Epoch 121

Valuation Office Agency matching

The match rates for Council Tax and Non-Domestic Rates for Epoch 121 are detailed as follows based on Valuation Office Agency (VOA) records up to 28 July 2025. The match rate is applicable to the AddressBase Premium product.

Data Source	Records Received	% Matched
Council Tax	27 246 694	99.91
Non-Domestic Rates	2 122 283	96.43

Next release

The next release of AddressBase products, Epoch 122, is scheduled for 16 October 2025.