Start with the cat you already have
Readiness for a second cat begins with an honest audit of the first one. A resident cat who is healthy, eating predictably, using the litter box reliably, and relaxed with ordinary household change is a candidate for a companion. A cat who is already hiding from visitors, over-grooming, missing meals, or recovering from illness, a move, or a loss is telling you her coping budget is spent, and adding a rival now risks turning stress behaviors into habits. Age and temperament shape the odds too: a young, playful cat usually welcomes a similar-aged companion, while a senior who has been an only cat for a decade may experience a newcomer as an intrusion no introduction method fully softens. If your cat has never lived with another cat, treat that as an unknown to manage slowly, not a disqualification.
The space and resource test, done with real numbers
Walk your home as if two cats who dislike each other must both live well in it, because during introductions that is the working assumption. You need a separate room with a closing door where the new cat can live for the first stage, complete with its own litter box, food, water, bedding, and scratching option. The standing resource rule is one litter box per cat plus one extra, placed in genuinely different locations rather than lined up side by side, and feeding stations far enough apart that neither cat must pass the other to eat. Check vertical and hiding resources as honestly as floor space: a small flat can work for two cats if shelves, perches, and quiet corners double each cat's usable territory, while a large house with one prized sunny spot can still generate daily conflict.
Time, routine, and the introduction workload
A second cat is ready to join your routine only if your routine can stretch for several weeks of deliberate management. Staged introductions mean feeding two cats on opposite sides of a door, swapping bedding, running separate play sessions, and supervising short meetings, every day, without letting the schedule collapse the first time work runs late. Beyond the introduction, the permanent load doubles in quiet ways: two carriers at vet visits, litter scooping that takes real minutes daily, play and attention that each cat expects from you individually, and holiday care that must cover two animals. If your current cat's care already slips when your week gets busy, that is the answer to the readiness question, whatever your floor plan says. The fix is either more slack in the routine or waiting until life provides it.
Money, timing, and the decision itself
Budget for a second cat as a full second set of costs, not a small top-up: food and litter roughly double, routine vet care doubles, and the emergencies that matter are the ones arriving for either cat in the same year. The new cat also deserves a vet visit of her own soon after arrival, before close contact with your resident cat, both for her health and to protect the cat you have. Timing rounds out the picture: avoid adopting into the middle of a house move, a new baby, building work, or a job change, because introductions need the household's calmest version of itself. When health, space, time, budget, and timing all pass, choose a newcomer whose age and energy complement your resident cat, and plan the arrival day like a project. Writing both cats' needs, costs, and introduction stages into KinsLe through Family Sharing gives every person in the home the same readiness picture before the new cat ever walks in.