Where is the serial number on a Samsung washer dryer?

Open the door and look at the front panel around the opening, usually low down; the rating plate is also on the back.

Around the door opening, on the rim of the drum
On the back panel

Source: Samsung UK – How to find the model and serial number of my Samsung product

How old is my Samsung washer dryer?

Copy the serial number from the plate, or paste everything on it.

All Samsung appliances