Making a Word text box with rounded corners instead of the default square corners is remarkably easy once you know the simple trick.
Word Text Boxes always start with square corners, no matter which default you choose from the gallery.
But once it’s inserted, a Word text box can be transformed many different shapes including Rounded Corners.
It’s the same text box with all the power that text boxes offer, just with a different shaped border.
Insert the text box and resize as usual. Select the box then go to Shape Format | Insert Shapes | Edit Shapes | Change Shape.
Select Rectangle: Rounded Corners
That’s it! That’s all there is to it.