If the wallpaper is stable, not peeling, and in good condition you can wallpaper over it. Wash it down so the new wallpaper will stick.

Hi! I have wallpapered over old wallpaper. Make sure your wallpaper is well adhered and clean. I prefer to remove old wallpaper, but, sometimes it's better left in place, which may be what you are dealing with. The reason the wallpaper must be spotless, is the self adhesive paper will adhere to any dirt, etc. and not adhere to the wall. You might want to use a wallpaper glue wallpaper instead, like I did. Good luck and stay safe!

Another vote for yes you can paper over it - but again only if the old wallpaper is in very good shape with the edges still glued down.

You can, but I would definitely ask at the paint store about the best technique. Sometimes they will tell you to prime over it with a prepping product.

I agree you could wallpaper over it, but personally, I would take down the old paper. It's not a hard job, just a bit of a pain.

I use a well soaked sponge and wet the old paper. This will really help remove it and it helps to start at a corner or seam so you are wetting the paper under the wallpaper.

Then used a plastic scraper and start picking at the paper. It will come up and you can start ripping it off.

I would use a primer first then paper or repaper the wall

No you don't have to. But it may not give you a completely smooth finish unless you remove the old layer first.

You don't have to remove the old paper; however, I always try to take a more longterm view of what I might want to do in the future. With that in mind, personally, I would remove the existing wallpaper. I've removed wall paper in the past to update homes and have found as many as 5 layers of oaoer! Not fun to remove!

You will most likely be sorry that you didn't remove the old wall paper. If you want a professional looking finish you need to start with a clean and level surface.

https://www.hometalk.com/3370217/best-way-to-remove-wallpaper

Best Way to Remove Wallpaper

If it is clean and no peeling, you can apply over existing.

You might be able to go right over it if it's stuck on enought. Otherwise use a steamer and peel it off.

You could probably go over it but know most peel and stick wallpaper doesn't block out what's behind it, you'll probably be able to see the old through the new. Do a little test part first.