Release waves explained: April, October and monthly updates

Business Central online is updated continuously. That means you no longer do big upgrades every three years, but you cannot ignore updates either. The article explains how major and minor updates arrive, what the update window and the update period mean, and what you can postpone. The information was checked against Microsoft Learn as it stood in October 2026. Use it to set a fixed rhythm for your company.

Major and minor updates

Microsoft releases two major updates a year, every April and October. In the other months, minor updates arrive with critical improvements, including regulatory changes. Most new functionality arrives in the major updates.

A new version is first generally available. About a week later it becomes available as an update to existing environments, but the timing can vary. You can see upcoming features in Microsoft's release plans.

The update window

Each environment has an update window that specifies when in the day Microsoft may update. By default it is between 8 p.m. and 6 a.m. local time. You can change it in the admin center, but the window must be at least six hours.

The update starts within the window. While it runs, users cannot sign in. If the update is not finished when the window ends, it is cancelled and tried again seven days later.

Postponing, and what you can do yourself

After a major version is released, you have an update period of five calendar months in which you can choose the date of the update. So you can postpone an update, but only within the period.

A one-month grace period follows, in which you cannot move the update to a later date. After that, Microsoft can uninstall extensions that block the update, so that it can be completed. Data in the extension is not deleted.

Administrators can choose the target version and date in the admin center, and set who receives notification emails. Check that emails from Microsoft do not end up in spam. Also remember that the update blocks sign-in while it runs, and schedule it so that it does not hit month-end.

Check the update window and time zone for each environment.
Keep notification recipients up to date.
Choose the update date when you know that tests are finished.
Test in a sandbox with a copy of production before you update production.
Use the preview about a month before a major release to test extensions.

If something goes wrong

Updates can fail, for example because a per-tenant extension or an app is not compatible. The environment then returns to the previous version, and a new attempt is scheduled seven days later. Notification recipients are informed.

Microsoft can also postpone an update if they find a critical error. Always check the current page on update cycles, as details can change.

Early features and a fixed rhythm

Some new features can be turned on in Feature Management before they become standard. That gives you time to test and prepare users. Some features are optional until the next major update and cannot be turned off afterwards. Always read the description before you turn something on in production.

Check Microsoft's release plans to see what is coming and what may affect your processes.

Set two calendar items a year: a test in a sandbox right after the preview and a scheduled update for production within the update period. Minor updates need a short check of key processes. Then updates become a routine, not a crisis.

Help with updates

Addverk is a new Business Central partner. We help plan and test updates. See our upgrade service and the prices page.