> For the complete documentation index, see [llms.txt](https://docs.os.uk/os-downloads/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.os.uk/os-downloads/products/addresses-and-names-portfolio/addressbase-fundamentals/release-notes/addressbase-products-june-2026-epoch-128.md).

# AddressBase Products June 2026 – Epoch 128

## Record counts

| Product                | Full Supply Record Count | Change-Only Update Record Count |
| ---------------------- | ------------------------ | ------------------------------- |
| OS Open UPRN           | 41 593 225               | N/A                             |
| AddressBase            | 30 952 312               | 135 790                         |
| AddressBase Plus       | 38 789 102               | 4 167 563                       |
| AddressBase Premium    | See rows below           | See rows below                  |
| Street                 | 1 530 418                | 8 576                           |
| Street Descriptor      | 1 654 788                | 5 398                           |
| BLPU                   | 41 593 225               | 1 208 933                       |
| Classification         | 45 377 303               | 173 882                         |
| LPI                    | 46 965 525               | 156 033                         |
| Organisation           | 1 389 948                | 15 603                          |
| Delivery Point Address | 31 068 483               | 65 596                          |
| Application Cross Ref. | 201 366 143              | 7 034 623                       |
| Successor              | 0                        | 0                               |

**Please note:**

* 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.
* 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            | 30 952 312      | 30 952 311              | 1              |
| AddressBase Plus       | 38 789 102      | 38 789 076              | 26             |
| AddressBase Premium    | See rows below  | See rows below          | See rows below |
| Street                 | 1 530 418       | 1 530 416               | 2              |
| Street Descriptor      | 1 654 788       | 1 654 786               | 2              |
| BLPU                   | 41 593 225      | 41 593 196              | 29             |
| Classification         | 45 377 303      | 45 377 272              | 31             |
| LPI                    | 46 965 525      | 46 965 495              | 30             |
| Organisation           | 1 389 948       | 1 389 946               | 2              |
| Delivery Point Address | 31 068 483      | 31 068 482              | 1              |
| Application Cross Ref. | 201 366 143     | 201 366 113             | 30             |
| 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](/os-downloads/products/addresses-and-names-portfolio/addressbase/addressbase-getting-started-guide/working-with-cou-data.md)' 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                  | 38 340 |
| Updates                  | 86 943 |
| Deletes                  | 10 507 |
| COU Populated Tile Count | 5 284  |

### AddressBase Plus

| Change Type              | Count     |
| ------------------------ | --------- |
| Inserts                  | 59 013    |
| Updates                  | 4 094 953 |
| Deletes                  | 13 597    |
| COU Populated Tile Count | 7 102     |

### AddressBase Premium

| AddressBase Premium Table | Inserts   | Updates   | Deletes   |
| ------------------------- | --------- | --------- | --------- |
| Street                    | 4 233     | 4 187     | 156       |
| Street Descriptor         | 4 275     | 966       | 157       |
| BLPU                      | 50 042    | 1 155 592 | 3 299     |
| Classification            | 60 594    | 96 900    | 16 388    |
| LPI                       | 63 478    | 88 525    | 4 030     |
| Organisation              | 4 783     | 6 821     | 3 999     |
| Delivery Point Address    | 38 725    | 16 379    | 10 492    |
| Application Cross Ref.    | 3 561 768 | 333 594   | 3 139 261 |

## Source data currency

The following information relates to the currency of the source data used in the creation of Epoch 128:

| Data Source                          | Date          |
| ------------------------------------ | ------------- |
| Royal Mail PAF                       | 22 April 2026 |
| National Land and Property Gazetteer | 22 April 2026 |
| One Scotland Gazetteer               | 21 May 2026   |
| VOA Non-Domestic Rates               | 19 May 2026   |
| VOA Council Tax                      | 19 May 2026   |
| OS MasterMap Topography Layer        | 12 May 2026   |
| OS MasterMap Highways Network        | 08 May 2026   |
| Code-Point with Polygons             | 01 April 2026 |
| Boundary-Line                        | 01 May 2026   |

## Data issues

### AddressBase

Details of live and resolved data issues for AddressBase will be communicated on the [AddressBase Known Data Issues page](/os-downloads/products/addresses-and-names-portfolio/addressbase/addressbase-known-data-issues.md). 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](/os-downloads/products/addresses-and-names-portfolio/addressbase-plus/addressbase-plus-known-data-issues.md). 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, Service Disruptions and Planned Maintenance page](/os-downloads/products/addresses-and-names-portfolio/addressbase-premium/addressbase-premium-known-data-issues-service-disruptions-and-planned-maintenance.md). This page will provide details of their impacts and updates on the expected time frame for their resolution.

## Improvements in Epoch 128

### Valuation Office Agency matching

The match rates for Council Tax and Non-Domestic Rates for **Epoch 128** are detailed as follows based on Valuation Office Agency (VOA) records up to **19 May 2026**. The match rate is applicable to the AddressBase Premium product.

| Data Source        | Records Received | % Matched |
| ------------------ | ---------------- | --------- |
| Council Tax        | 27 472 486       | 99.98     |
| Non-Domestic Rates | 2 131 965        | 96.52     |

## Next release

The next release of AddressBase products, **Epoch 129**, is scheduled for **06 August 2026**.

### **VOA Resync – Address data update (planned maintenance)**

A VOA resynchronisation activity is being undertaken to correct and align address data, improving overall data currency and completeness. The update is expected to introduce a higher-than-normal volume of changes (\~75,000 records), resulting in larger COU files for affected products.

The changes will be reflected in **Epoch 129** for AddressBase Premium.

### Customer impact

Customers should expect increased file sizes and a higher volume of change records in the relevant epoch; no service downtime is anticipated.


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