Starting October 1, 2026, Microsoft is changing how license keys work for Dynamics 365 Business Central on-premises and for Dual Use Rights (DUR) scenarios. Version-specific keys go away, replaced by a single “28+” key family. The change simplifies things on paper, but it adds a step to every upgrade: you must download a fresh license file to unlock the objects of the new version.
If you maintain on-premises or DUR environments, here is what changed and what to put on your upgrade checklist.
What changes with the 28+ license key?
Effective October 1, 2026, new releases of Dynamics 36 Business Central no longer include version-specific license keys for on-premises. For version 28 and later, “28+” is the license key version that applies. This covers every on-premises edition, including DUR licenses for Dynamics 36 Business Central online customers.
At each new version release on or after October 1, 2026, you must download a refreshed 28+ key if you want to upgrade to the latest version. The date on which you download the key determines which objects are unlocked in the license file.
Example: Dynamics 365 Business Central version 30 is due in April 2027. Once it is released, you download a new 28+ key, and that key unlocks the version 30 objects. If you try to run version 30 with a 28+ key you downloaded on October 1, 2026, you get a version compatibility warning.
One temporary quirk: DUR keys downloaded from the Microsoft 365 Admin Center show “28” at first. This label will be corrected to “28+” by the second week of October.
Dual Use Rights: a separate six-month rule.
Don’t confuse this with an earlier change. Since June 5, 2026, customers who run on-premises Business Central through Dual Use Rights must download and replace their license keys every six months. Each key is tied to the active subscription term plus a short buffer, and new or replacement keys come from the Microsoft 365 Admin Center.
If a key expires and is not replaced, the on-premises environment stops working. Using it past expiry, even during the buffer period, is not allowed. The online subscription must also stay active, since the on-premises access depends on it.
The two rules are independent:
| Rule | Applies to | When you act |
|---|---|---|
| 28+ key refresh | All on-premises editions, DUR included | Before each version upgrade |
| Six-month key renewal | DUR deployments only | Every six months |
What to do now?
- Add “download the refreshed 28+ key” to every on-premises upgrade checklist, before importing the license with
Import-NAVServerLicense. - Download the key only once the target version is released, since the download date decides which objects are unlocked.
- Identify every environment running under Dual Use Rights.
- Record each DUR key’s expiry date and set reminders 30 and 7 days before it.
- Tell customers and colleagues who manage on-premises servers that keys are now an ongoing task, not a one-time setup.
