One card per component, because dates split
A single vet visit can leave your cat with boosters that next fall due at different times. One fridge card for the visit, carrying one date, will be wrong for at least one component — and it will be wrong in the dangerous direction, showing the later date while the earlier one passes. A card per component, each with its own due date, costs a little more fridge space and removes that trap entirely.
Write the component name exactly as it appears on the vaccination certificate. Your own shorthand may make sense today, but in a year, or in another family member's hands, the certificate's wording is what the clinic will use when you call to book.
Designing the card to be acted on, not just noticed
Put the due date at the top in your largest writing, the book-by date — a few weeks before — at the bottom in a box, and between them the cat's name, the component, and the clinic's name. The book-by date is the operative one: households act on booking prompts, while due dates themselves often get noticed only once they are close or past.
Clip each card separately rather than stacking them under one magnet. Stacked cards hide each other, and the hidden one is predictably the one that matters. Spread them in a row at eye level, in due-date order left to right, so the leftmost card is always the next job.
Living with the cards through the year
When you book an appointment, write the appointment date and time on the card itself. The card then answers the household's two questions — when is it due, and is it booked — at a glance, and anyone opening the fridge can see that the job is in hand rather than duplicating it.
After the visit, that card comes down and a new one goes up in the correct position in the row, written from the new certificate the same day. Keep the finished cards in an envelope inside a kitchen drawer for a year; if a question arises about when a booster was given, the old cards reconstruct the sequence quickly.
When fridge space serves more than one cat
Give each cat a separate row of cards, labelled with the cat's name on a strip above the row. Rows prevent the mix-up where one cat's card is read as another's — a real risk when names are small and mornings are rushed. If fridge space runs out, move to the side panel of the fridge rather than shrinking the writing; legibility at a glance is the system's whole value.
Replace any card that gets splashed, faded, or curled, copying the details from the certificate rather than from the damaged card, so errors do not get faithfully copied forward.
Photograph the row of cards once a month. Fridge doors get wiped, cards fall during a deep clean, and a dated photo lets you rebuild the row in minutes with the order and the book-by dates intact, instead of reconstructing the system from certificates under time pressure.
The fridge row keeps the next booster in daily view, and KinsLe's Pet Passport keeps the certificates and dates behind those cards gathered in one packet, so proof is ready for a new vet, a cattery, or an emergency visit.