Primer undercoat

Called into our local paint store for some water based undercoat in white, but all he has is primer undercoat, will this do ok or is there a difference?

I have found that 'Primer and Undercoat' as one product costs more than separately buying Primer and Undercoat.
But as a DIYer I use it because it is easier to pay more and just have one can in shed.
Also great for painting wood where I have some painted areas and some bare wood - as I can simply paint both without thinking.

I find the 'Primer and Undercoat' that I use works very well in all situations, and not had any issues painting over paint (where a primer is not normally needed).

SFK

for indoor work, white acrylic primer undercoat is adequate. It goes on easily and dries quickly. Being water-based, it may raise the grain a little, but presumably will not be damp for long.

You can wipe it very gently with fine sandpaper to remove flies or dust between coats, but modern water-based paints can be very difficult to sand as they may ball up under the paper, so do any other sanding before you start to paint.

It will last longer in a plastic tub with a plastic lid that snaps sealed. Metal tins may rust due to the water content.