Filling Down or Filling Up Missing Data in Power Query

In this blog, you will learn how to fill missing data in Power Query in Power BI. This is an important and common step in data cleaning, especially when working with incomplete datasets.

Sometimes, when you import data into Power BI, some columns may have blank values because the information is only mentioned once for a group of rows—like region names, product categories, or department names and the rest of the rows stay empty.

We will fix this problem using Power Query’s Fill Down and Fill Up options. This will help ensure that every row has the right information and is ready for proper analysis and reporting.

Filling down (or up) ensures that every row carries the right information by copying values into the empty cells. Let’s understand this with an example.

Sample Dataset (Sales):

Problem:

In the Region column, the region name appears only once, and the remaining rows are left blank. We want each product row to show its corresponding region.

Open Power Query Editor:

• Go to Home → Transform data.
• Select the Table: In Power Query, select the table containing your data (e.g., Sales).

Fill Down and Fill Up only work when the cells contain null values, not blanks. Make sure the blank values are converted to null.

Right-click on the column name, select Replace Values, leave the “Value to Find” box empty, and type null in the “Replace With” box. Then click OK.

Fill Down Missing Values:

• Select the column, go to the Transform tab, and click on Fill Down.
• Power Query will automatically fill down the last non-blank value into the blank cells below it.

Another way: Right-click on the Region column → Select Fill, then Down.

See the result:

Apply Changes:

• Once the blanks are filled, go to Home → Close & Apply.

(Optional) Fill Up:

If the required data was below the empty cells, you could use Fill Up by right-clicking and selecting Fill Up instead.

Thanks for reading this post! I hope you found it helpful. Feel free to share it with others or your teammates so they can benefit from it too. 😊