The two systems do different jobs
A microchip is invisible and permanent: it identifies the horse only when someone scans it, which makes it the proof-of-identity backbone. A freeze mark is visible and deterrent: anyone can see and read the characters from a distance, which discourages theft and makes a loose horse traceable by a member of the public without equipment. Choosing between them is really choosing which job matters more to you, and many yards answer with both.
How microchipping works in practice
Only a vet implants the chip. The site — the ligament on the left side of the neck — is cleaned, sometimes clipped, and the chip is injected through a wide needle; the whole appointment takes minutes and most horses need no sedation. The vet scans the chip before and after to confirm the number, and that number is registered against your name, address, and phone numbers on the chip database. The step owners forget is maintenance: if you move house or change numbers, the registration must be updated, because an out-of-date chip record identifies the horse but not how to reach you.
How freeze-marking works in practice
Freeze-marking is carried out by specialist companies rather than vets. The horse is clipped over the marking site — commonly the saddle area, so the mark hides under tack but shows in the field — and irons chilled to very low temperatures are pressed on for carefully timed seconds per character. The process stops the colour-producing cells in the hair follicles working, so the regrowth is white and permanent. On grey horses, where white hair would not show, a longer application produces a hairless mark instead. There is brief discomfort and some local swelling, and the mark sharpens over the following weeks as the coat regrows.
Registration and paperwork either way
Neither system is finished when the procedure ends. The chip number or mark characters need to match what is written in the horse's passport and ownership paperwork — a mismatch between the mark on the shoulder and the document in the drawer creates exactly the doubt identification exists to remove. Keep photographs of a freeze mark with the paperwork, note the chip number in more than one place, and tell any buyer, loaner, or yard manager which systems the horse carries and where the records live.
Which horses benefit most
Free-roaming, loaned, and competition horses gain most from a visible mark, because strangers handle and see them. Horses at livery, where scanners are routine at arrival, are well served by the chip alone. Foals are typically chipped when their first paperwork is done, and a mark can be added once they are in work and the saddle area is defined. Whichever route you take, check the details against the current rules for your region, since identification requirements for horses vary and are updated. Once the numbers exist they need to live somewhere findable, and KinsLe's Pet Pass puts your horse's chip and freeze-mark numbers on its verified ID card beside your contact details, ready to show anywhere.