Cat peeing outside the litter box? It's almost always one of these three things

This might be the most common cat problem there is, and people jump straight to "my cat is mad at me." Cats don't do revenge. Here's the actual checklist, in order: 1. Medical. Rule this out first, always. UTIs, bladder crystals, and idiopathic cystitis all cause box avoidance because the cat associates the box with pain. IMPORTANT: if you have a male cat straining in the box and producing nothing, that's a potential urethral blockage and it is an emergency. Not a tomorrow thing, a right now thing. Blocked cats can die within a day or two. 2. The box itself. The standard advice from vets is one box per cat, plus one extra. Two cats, three boxes. Scoop daily. A lot of cats hate covered boxes because smell concentrates in there and they can't see an exit. Location matters too, nobody wants to use a toilet next to a roaring washing machine. 3. Stress. New pet, new baby, moved apartments, construction noise, even rearranged furniture. Cats are routine animals and stress shows up in their bladder more than anywhere else. Cornell's Feline Health Center has a really good free writeup on this if you want to go deep. Whatever you do, don't punish them for it. Punishment adds stress, and stress is often the cause. You end up in a spiral.