The one-per-cat plus one rule, and why it works
Get the count right and most tray problems never start: allow a dedicated tray for every cat in the home, then add one spare on top. One cat therefore needs two trays, two cats need three, and so on. The extra tray is not indulgence. Cats often prefer to urinate and defecate in different places, and a tray already used since your last scoop may be unacceptable to a fastidious cat even if it looks fine to you. A spare also covers the day a tray is being washed, the hour another cat is guarding the hallway, or the week your cat simply decides she dislikes one location. In a single-cat home people often skip the second tray and get away with it until illness, a house move, or old age makes the margin matter, which is why starting with two is the safer habit. Kittens and senior cats may need trays closer to where they spend their time rather than a strict count alone.
Placement matters as much as the number
Two trays side by side in the laundry room count, from your cat's point of view, as one location. Spread them across genuinely different, quiet areas she can reach at all hours, such as a bathroom corner and a calm spot near where she sleeps. Avoid placing a tray beside washing machines, boilers, or doors that slam, because a single fright mid-use can put a cat off that spot for weeks. Keep trays well away from food and water bowls, since cats instinctively separate eating from toileting. On each floor of a multi-storey home there should be at least one tray, so an older cat with stiff joints is never faced with stairs when she needs to go urgently. Choose an entry height she can manage, and for covered trays check that the hood does not trap smell inside or make a large cat feel cornered with no escape view.
Choosing the tray and litter to go in those spots
Size is the most common mistake. A tray should be long enough for your cat to turn around in comfortably, which for many adult cats means larger than the small trays sold for kittens. Most cats prefer a fine, unscented, clumping litter at a depth they can dig in without hitting the base immediately. If you want to change litter type, put the new litter in the spare tray first and let your cat vote with her feet rather than switching every tray at once. Liners, crystals, and strongly scented litters suit some households and repel some cats, so treat your cat's consistent use as the verdict. Keep the setup in each location boringly identical once she approves it, because novelty that delights people often unsettles the animal actually using the tray.
Keeping several trays clean without it becoming a chore war
More trays only help if all of them stay clean, so build a short rota instead of relying on whoever notices first. Scoop each tray daily, top up litter as needed, and empty and wash one tray at a time on rotation with warm water and a mild unscented cleaner so a familiar-smelling tray is always available. Note which tray your cat uses most, as a sudden switch in preference can be an early clue that a location has become noisy, draughty, or contested by another pet. If accidents appear despite the right number of trays, look at access and competition before assuming the count is wrong. KinsLe Care Teams makes that rota explicit by letting you assign each tray's daily scoop and weekly wash to a named person, with completions timestamped so gaps are easy to spot.