Same spot, every time? That's a signal, not spite.

The short answer: if it's marking — small amounts, often on vertical surfaces, in specific repeated spots, in a cat that otherwise uses the box — this is fixable, usually for nothing. If your cat is urinating large volumes outside the box, straining, or crying, stop reading and call a vet. That second list is a medical emergency, not a behaviour problem.

Free things to try first

I'd genuinely rather you fixed this for nothing, so: the standard rule is one litter box per cat plus one spare, each in a spot with two ways out and away from noisy appliances. Cats avoid boxes where they can be cornered. And any spot already marked has to be treated with an enzyme cleaner, not vinegar — otherwise the smell keeps telling the cat this is the place.

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If you've done all that and it continues

Then it's behavioural rather than environmental — and it's almost always stress or territory, not defiance. Cats don't do spite. Something in the environment changed and the marking is the report.

The useful exercise is narrow: write down what changed in the four weeks before it started. A new pet. A new person, or one who left. Building work. A cat visible through a window. Furniture moved. A different schedule. Naming the trigger is most of the work, because you can usually blunt it — block the window sightline, give the resident cat a high perch of its own, reintroduce animals slowly.

And keep treating every marked spot with enzyme cleaner while you do it. A spot that still carries the scent keeps inviting a repeat, and you'll think the behaviour work failed when it was the cleaning that did.