> 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-premium/addressbase-premium-known-data-issues-service-disruptions-and-planned-maintenance.md).

# AddressBase Premium Known Data Issues, Service Disruptions and Planned Maintenance

This page provides the details of known data issues and service disruptions impacting the AddressBase Premium product. It also provides information on any planned maintenance periods.

## Live known data issues

There are no live known data issues for AddressBase Premium at this time.

## Service disruption

There are no live service disruptions affecting AddressBase Premium at this time.

## Planned maintenance: 25 June 2026

### **Maintenance description**

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 AddressBase Premium **Epoch 129** scheduled for release on **25 June 2026.**

### **Impacts of the maintenance**

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

{% hint style="info" %}
To report an issue not currently listed here, please visit the ['Contact us' page on the OS website](https://www.ordnancesurvey.co.uk/contact-us/business-government/use-os-data).
{% endhint %}


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