Power Query’s Index Column numbers every row and renumbers when you refresh, so new or removed rows never break the sequence. You can start at any number and add prefixes like INV-0150.
Step 1: Load the data
Click in the data → Data → From Table/Range → OK.
Step 2: Add the index
Add Column → Index Column → From 1. Rename the column (double-click its header) and move it with right-click → Move → To Beginning.
Step 3: Load and refresh
Home → Close & Load To → Existing worksheet. When the source changes, right-click the result → Refresh.
Custom start and prefix
Choose Index Column → Custom to set the starting number and step, for example start 150, step 1.
For a code like INV-0150, add a Custom Column:
"INV-" & Text.PadStart(Text.From([Index]), 4, "0")Or use Add Column → Format → Add Prefix for a simple prefix without padding.
Number within groups
To restart numbering for each group, such as each region, use Group By with All Rows, add an index inside each group with a custom column Table.AddIndexColumn([Rows],"No",1), then expand.