In this video, I explain the new DAX User-Defined Functions (UDFs) in Power BI – what they are, how to enable them in the September 2025 update, and why they’re useful. Think of UDFs as a way to package DAX logic into a reusable function, just like custom functions in Power Query. I’ll show you how to create and test functions in the DAX Query View, use them in measures, tables, and visual calculations, and even build cleaner things like a Calendar function. Along the way, I’ll also share a few quirks and limitations you should know about. If you write DAX regularly, this is a feature you’ll definitely want to try.
