Transitioning from Codeunit 1 to System Codeunits


If you're coming from version 13 or earlier, Business Central Spring 2019 (v14) is a required step to upgrade to the latest version of Business Central. However, mainstream support for version 14 ends in October 2023, and minor updates to the version are no longer available. New customers can't use version 14 in production, but only as a path for upgrading to latest version. Existing customers on version 14 remain supported by Microsoft as defined in the Fixed Lifecycle Policy.

All version 14 updates are compatible for upgrade with Business Central 2024 release wave 1 (version 24) and later release waves.

With Business Central, codeunit 1 Application Management has been removed and replaced with new System codeunits. No functionality has been removed by this change. All system method triggers, event publishers, and their code have been moved to other codeunits.

However, this change will affect the upgrade process from Dynamics NAV and how you develop from now on.


The foundation of this change is events - publishers and subscribers. System codeunits don't contain code. They only contain event publishers. Instead of running codeunit 1 and calling respective functions, Business Central Server runs system codeunits. The system codeunits will in turn raise published events. There are various management codeunits that subscribe to these events. Like codeunit 1, these subscriber codeunits contain method triggers and integration event publishers. They can call application functionality and raise events. The following figure illustrates the process:

System event publishers.

About system codeunits

  • They have IDs in the 2 billion range.
  • You can't modify them.
  • Currently, we don't recommend that code subscribes to the events in the new system codeunits 2000000001..2000000010 directly. Although not blocked, it might be in a future release. Instead, you should subscribe to one of the integration events.

Mapping Codeunit 1 method triggers to events

The following table lists the mappings between the codeunit 1 triggers and the new method triggers/publishers in the management codeunits.

Codeunit 1 trigger New codeunit ID New codeunit name New method
CompanyClose 40 LogInManagement CompanyClose
CompanyOpen 40 LogInManagement CompanyOpen
GetSystemIndicator 40 LogInManagement GetSystemIndicator
OnAfterCompanyClose 40 LogInManagement OnAfterCompanyClose
OnAfterCompanyOpen 40 LogInManagement OnAfterCompanyOpen
OnBeforeCompanyClose 40 LogInManagement OnBeforeCompanyClose
OnBeforeCompanyOpen 40 LogInManagement OnBeforeCompanyOpen
FindPrinter 44 ReportManagement GetPrinterName
ApplicationVersion 9015 Application System Constants ApplicationVersion
CustomApplicationVersion N/A N/A
ReleaseVersion 9015 Application System Constants ReleaseVersion
ApplicationBuild 9015 Application System Constants ApplicationBuild
CustomApplicationBuild N/A N/A
ApplicationLanguage 43 LanguageManagement ApplicationLanguage
DefaultRoleCenter 9170 Conf./Personalization Mgt. DefaultRoleCenterID
MakeDateTimeText 41 TextManagement MakeDateTimeText
GetSeparateDateTime 41 TextManagement GetSeparateDateTime
MakeDateText 41 TextManagement MakeDateText
MakeTimeText 41 TextManagement MakeTimeText
MakeText 41 TextManagement MakeText
MakeDateTimeFilter 41 TextManagement MakeDateTimeFilter
MakeDateFilter 41 TextManagement MakeDateFilter
MakeTextFilter 41 TextManagement MakeTextFilter
MakeCodeFilter 41 TextManagement MakeTextFilter
MakeTimeFilter 41 TextManagement MakeTimeFilter
AutoFormatTranslate 45 AutoFormatManagement AutoFormatTranslate
ReadRounding 45 AutoFormatManagement ReadRounding
CaptionClassTranslate 42 CaptionManagement CaptionClassTranslate
GetCueStyle 9701 Cue Setup GetCueStyle
SetGlobalLanguage 43 LanguageManagement SetGlobalLanguage
ValidateApplicationlLanguage 43 LanguageManagement ValidateApplicationLanguage
LookupApplicationlLanguage 43 LanguageManagement LookupApplicationLanguage
GetGlobalTableTriggerMask 49 GetGlobalTableTriggerMask
OnGlobalInsert 49 GlobalTriggerManagement OnGlobalInsert
OnGlobalModify 49 GlobalTriggerManagement OnGlobalModify
OnGlobalDelete 49 GlobalTriggerManagement OnGlobalDelete
OnGlobalRename 49 GlobalTriggerManagement OnGlobalRename
GetDatabaseTableTriggerSetup 49 GlobalTriggerManagement GetDatabaseTableTriggerSetup
OnDatabaseInsert 49 GlobalTriggerManagement OnDatabaseInsert
OnDatabaseModify 49 GlobalTriggerManagement OnDatabaseModify
OnDatabaseDelete 49 GlobalTriggerManagement OnDatabaseDelete
OnDatabaseRename 49 GlobalTriggerManagement OnDatabaseRename
OnDebuggerBreak N/A N/A
LaunchDebugger N/A N/A
OpenSettings 9170 Conf./Personalization Mgt. OpenSettings
OpenContactMSSales 50 SaaS Log In Management OpenContactMSSales
InvokeExtensionInstallation 2501 ExtensionMarketplaceMgmt InvokeExtensionInstallation
CustomizeChart 9180 Generic Chart Mgt CustomizeChart
HasCustomLayout 44 ReportManagement HasCustomLayout
MergeDocument 44 ReportManagement MergeDocument
ReportGetCustomRdlc 44 ReportManagement ReportGetCustomRdlc
ReportScheduler 44 ReportManagement ScheduleReport
OnBeforeOpenSettings 9170 Conf./Personalization Mgt. OnBeforeOpenSettings
OnAfterGetApplicationVersion 9015 Application System Constants OnAfterGetApplicationVersion
OnRoleCenterOpen 9170 Conf./Personalization Mgt. OnRoleCenterOpen
OnAfterGetSystemIndicator 79 OnAfterGetSystemIndicator
OnAfterFindPrinter 44 ReportManagement OnAfterGetPrinterName
OnAfterGetDefaultRoleCenter 9170 Conf./Personalization Mgt. OnAfterGetDefaultRoleCenter
OnAfterMakeDateText N/A N/A
OnAfterMakeTimeText N/A N/A
OnAfterMakeText N/A N/A
OnAfterMakeDateTimeFilter 41 LanguageManagement OnAfterMakeDateTimeFilter
OnAfterMakeDateFilter 41 LanguageManagement OnAfterMakeDateFilter
OnAfterMakeTextFilter 41 LanguageManagement OnAfterMakeTextFilter
OnAfterMakeCodeFilter N/A N/A
OnAfterMakeTimeFilter 41 LanguageManagement OnAfterMakeTimeFilter
OnAfterAutoFormatTranslate 45 AutoFormatManagement OnAfterAutoFormatTranslate
OnAfterCaptionClassTranslate 42 CaptionManagement OnAfterCaptionClassTranslate
OnAfterGetGlobalTableTriggerMask 49 GlobalTriggerManagement OnAfterGetGlobalTableTriggerMask
OnAfterOnGlobalInsert 49 GlobalTriggerManagement OnAfterOnGlobalInsert
OnAfterOnGlobalModify 49 GlobalTriggerManagement OnAfterOnGlobalModify
OnAfterOnGlobalDelete 49 GlobalTriggerManagement OnAfterOnGlobalDelete
OnAfterOnGlobalRename 49 GlobalTriggerManagement OnAfterOnGlobalRename
OnAfterGetDatabaseTableTriggerSetup 49 GlobalTriggerManagement OnAfterGetDatabaseTableTriggerSetup
OnAfterOnDatabaseInsert 49 GlobalTriggerManagement OnAfterOnDatabaseInsert
OnAfterOnDatabaseModify 49 GlobalTriggerManagement OnAfterOnDatabaseModify
OnAfterOnDatabaseDelete 49 GlobalTriggerManagement OnAfterOnDatabaseDelete
OnAfterOnDatabaseRename 49 GlobalTriggerManagement OnAfterOnDatabaseRename
OnAfterHasCustomLayout 44 ReportManagement OnAfterHasCustomLayout
OnAfterReportGetCustomRdlc 9650 Edit MS Word Report Layout OnAfterReportGetCustomRdlc
OnBeforeOnDatabaseInsert 49 GlobalTriggerManagement OnBeforeOnDatabaseInsert
OnBeforeOnDatabaseModify 49 GlobalTriggerManagement OnBeforeOnDatabaseModify
OnBeforeOnDatabaseDelete 49 GlobalTriggerManagement OnBeforeOnDatabaseDelete
OnBeforeOnDatabaseRename 49 GlobalTriggerManagement OnBeforeOnDatabaseRename
OnEditInExcel 6710 OnEditInExcel
OnInstallAppPerDatabase N/A N/A
OnInstallAppPerCompany N/A N/A
OnCheckPreconditionsPerDatabase 9900 OnCheckPreconditionsPerDatabase
OnCheckPreconditionsPerCompany 9900 RaiseOnCheckPreconditionsPerCompany
OnUpgradePerDatabase 9900 OnUpgradePerDatabase
OnUpgradePerCompany 9900 OnUpgradePerCompany
OnValidateUpgradePerDatabase 9900 OnValidateUpgradePerDatabase
OnValidateUpgradePerCompany 9900 OnValidateUpgradePerCompany

What does this mean for upgrade?

Full upgrade - application code and data

Move custom logic from the old codeunit 1 to the management codeunits and methods. Change custom code that call into codeunit 1 to call or subscribe to the new methods. You can do this step as part of the application code upgrade.

Technical upgrade

After you convert the old database to the Business Central platform, import and compile the replacement codeunit 1 object. You get the replacement object from Codeunit 1 Replacement.

See Also

Converting a Database