3 cats one scratching post? Here's the fix

Three sibling cats sharing a single scratching post is a recipe for exactly what you're describing — when the post is occupied or feels like contested territory, they go find their own spot, and that spot is usually your sofa. Scratching is completely normal behaviour: they're conditioning their claws and leaving scent marks, so the goal isn't to stop it, just to redirect it. With three cats you essentially need enough posts that no individual ever has to queue or compete. Before I point you in the right direction — are they mostly scratching vertical surfaces like chair legs and door frames, or are any of them going for horizontal surfaces like carpet or rugs? And is the furniture they're targeting fabric, leather, or a mix?

That's a really clear pattern — the loser of the post competition is immediately self-soothing on the nearest vertical fabric surface. Totally logical from the cat's perspective. The fix is straightforward: you need at least three tall, stable vertical posts, ideally one per cat, and placed right next to the furniture they're currently targeting so the redirect is obvious. Height matters a lot — a post they can fully stretch on feels genuinely satisfying, and most cheap posts are too short. What does your current post look like — roughly how tall is it, and what's it covered in?

Fifty centimetres is on the short side for adult cats — they really want to be able to fully extend, which for most cats means 70cm or taller. And carpet covering is fine but sisal rope is more satisfying for most cats and tends to hold their interest better long-term. My clear recommendation for your situation is the SmartCat Ultimate Scratching Post. It's 82cm tall, which is genuinely full-stretch height, and it's covered in woven sisal that most cats go for immediately. Crucially it has a very heavy, wide base so it doesn't wobble — a wobbly post is one of the main reasons cats reject a post and go back to furniture. Get three of them, position one right next to each problem spot on the sofa and chair, and the competition disappears because there's suddenly no scarcity. It's available on Amazon UK and holds up well with multiple cats.

Spread them out, but prioritise placing them right next to the spots they're currently scratching — that's the most important move. When you put a post directly beside the damage site, you're giving them a better option in the exact moment they feel the urge. Once they're reliably using the posts you can gradually inch them a foot or two away if you want them less prominent, but don't move them until the habit is properly formed. Siblings often spread out through the house anyway, so having one in the main living area, one near a bedroom or wherever the armchair is, and one in a secondary space they use tends to cover it well.

Perfect — three is exactly the right call. One thing worth doing on day one: rub a tiny bit of catnip on the base of each post if they respond to it, or just let them investigate at their own pace. Most cats clock a tall sisal post pretty quickly. You should notice the furniture incidents dropping off within a week or two once the competition pressure is gone.