Business Central upgrade considerations and preparation for v26 and later

This article provides important information and tips for things to consider when you prepare to upgrade to 2025 release 1 (version 26) or 2025 release 2 (version 27). The information that's relevant for you depends on which version you're upgrading from, and how much your solution differs from the Business Central base application.

Deprecated or redesigned functionality

Business Central occasionally deprecates features in application and platform. In most cases, features are replaced by more modern and sustainable features. If you're upgrading a solution that depends on the deprecated or changes functionality, you might have to change application code as part of the upgrade process.

For example, sometimes code is refactored so that fields are no longer used. Or the functionality is moved from the base application to an extension. Typically, if you have custom extension code that depends on these fields, you have to create a new version of the extension to handle the change.

Learn more about the deprecated features in:

Deleted objects

APPLIES TO: Upgrade from v24.0 and earlier only

Many tables and fields are deleted from the base application and other Microsoft extensions in Business Central. These objects were in the Obsolete::Removed state for more than one major release. For a complete list of the deleted objects, consult Deleted objects in 2025 release wave 1.

This change aligns with the cleanup cycle that occurs every fifth release. Learn more in the blog post Essential cleanup guide for partners: 2025 release wave 1.

Effect on upgrade

Complete these tasks before upgrading to version 26 later:

Refactor custom code in non-Microsoft extensions, including upgrade code, to replace or remove references to these objects.
Upgrade versions 24 or earlier to 25 before upgrading to version 26.0 and later.

Schema changes in subscription billing extension

APPLIES TO: Upgrade from v25.0 only

Version 25.0 introduced the Subscription & Recurring Billing extension. In version 26 and later, the extension is renamed to Subscription Billing. Several tables and fields in the extension are renamed, causing breaking changes when upgrading the extension from version 25.0 to 26.0 or later.

To upgrade the extension, you must synchronize the extension's database schema with the tenant database schema using a force sync operation. Force sync can cause data loss if custom code depends on the renamed tables and fields in the extension. To avoid data loss, refactor the custom code to match the extension's latest database schema before upgrading. For a list of renamed tables and fields, see Renamed tables and fields.

Performance and upgrade considerations for installed extensions

Installing a large number of apps (extensions) in your Business Central environment can negatively impact performance and upgrade operations.

Installing a large number of apps (extensions) in your Business Central environment can negatively impact performance in several ways:

Slower environment startup - Each installed extension adds to the initialization time when the environment starts or restarts. The system must load and initialize all installed extensions, even if they're not actively used.
Longer upgrade times - Environment upgrades must process all installed extensions, which increases the overall upgrade duration. This impact grows with the number of extensions installed.
Increased risk exposure - Extensions from untrusted sources can introduce security vulnerabilities or unexpected performance issues.

General guidelines

Install only the extensions that are required for your business processes.
Ensure that extensions come from sources you trust.
Regularly review installed extensions and remove those no longer needed.

Data retention after uninstallation

When an extension is uninstalled, its data remains in your database by design. This allows you to reinstall the extension later without data loss. However, this preserved data can have negative consequences:

Increased database size - Orphaned extension data consumes database space that could be used for active business data.
Slower runtime performance - The database must manage companion tables for uninstalled extensions, which can slow down data operations.
Longer upgrade times - Environment upgrades process all tables in the database, including those from uninstalled extensions.

Clean up orphaned extension data

Use the Delete Orphaned Extension Data page to identify and remove data from uninstalled extensions. This maintenance task:

Frees up database capacity
Reduces the row size in companion tables used to store extension data
Speeds up data operations on affected tables
Reduces upgrade complexity and duration

Learn more:

This section includes important deployment changes that are helpful to know when from coming from a version 22 and earlier deployment. These changes were introduced in version 23.0. These changes don't affect the upgrade process, just the deployment.

The default port for client services port for Business Central Server changed to 7085 instead of 7046. You can still use 7046, but you have to change the port number in the Business Central Server instance configuration. Learn more in Configuring Business Central Server.
NET Core no longer supports Server principle names (SPN). This change affects the delegation from the Business Central Web Server to the Business Central Server when they're on different computers.

The affected scenarios are described in Deploying Business Central in a Two-Computer Topology and Deploying Business Central in a Three-Computer Topology.

Learn more about setting up delegation in Configuring Delegation for Business Central Web Server. You can do this task anytime, but after upgrade, users won't be able to sign in to the web client until you do.

Upgrading the Application Code
Upgrading the Data
Deprecated Fields, and Fields Marked as Obsolete

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Last updated on 2025-12-04