Power BI makes DAX user-defined functions generally available
Reviewed by Helen Jones
Microsoft published the Power BI June 2026 feature summary on 9 June and updated it on 12 June. The update makes DAX user-defined functions generally available so authors can define a calculation once and reuse it across measures, calculated columns and visual calculations. Function definitions can also be saved as TMDL files in Git-integrated workspaces.
Before this release, analysts often copied the same business logic across measures and reports. One small metric change then meant hunting through every copy and hoping the totals still matched Excel, finance, or the source system. Reusable DAX functions reduce duplicated code, but they do not define the business meaning of a metric. A bad definition in one reusable place is still bad; it is just easier to reuse.
Analysis
Before writing a DAX function, list the three measures you copy most often and write one plain-English definition for each. Only turn the measure into a function when that definition is agreed.
Source note
Pulse published by Collab365 Spaces, reviewed by Helen Jones on . Cite as "Power BI makes DAX user-defined functions generally available", Collab365 Spaces. 1 source referenced.