Mix 1 tbsp. of baking soda with water to create a paste, and wipe down the walls to neutralize the cat's urine odor. The urine's enzymes are strong and lures the cat back to the same spot unless it is neutralized to remove the odor. Tape a plastic sheet against the walls to protect them from the cat's urine until the marking issues subside.
Spray cat repellent on the furniture's surface and along the wall's edges. If a cat tends to urinate in a specific area, the cat repellent spray contains an odor that will keep the cat away, and is safe to use.
Lay a waterproof pad on your furniture. The couch and bed tend to be favorite sleeping spots for cats, and are also susceptible to cat urination. You can also use clear plastic runners, turned upside down so that the prickly nubs on the runner are facing up. Your cat won't be able to walk on it.
Spray Feliway onto the edges of the couch and along the edge of the wall. Feliway is a pheromone spray that soothes cat anxiety by reproducing pheromones naturally produced by the cat.