Best Microchip Cat Flap UK: Which One Suits Your Cat and Door?

A microchip cat flap only unlocks for cats whose microchip it has learned. Your own cat walks in using the chip your vet already fitted, and the neighbour's tom stays outside. For most cats the SureFlap Microchip Cat Flap is the safe choice. If your cat is big or you want it kept in at night, go for the larger SureFlap Microchip Pet Door with its curfew timer. Add the Connect version and hub only if you want to see comings and goings on your phone.

How a microchip cat flap works

There is a small reader in the tunnel that picks up the microchip under your cat's skin. You put the flap into learning mode, let your cat put its head into the tunnel and the flap stores the chip number. From then on the latch only releases for the animals it knows.

On most microchip flaps the reader sits on the outside only. Going out is free for any animal, coming in is checked. That way a stray cat that slipped in through an open window can still leave. If you have one cat that must stay indoors and one that may go out through the same flap, you need a flap that also reads on the way out, such as the SureFlap DualScan.

Will it work with my cat's microchip?

In England almost certainly yes, because your cat should already have a chip. Since 10 June 2024 every pet cat in England must be microchipped and registered on an approved database by the time it is 20 weeks old, indoor cats included. Owners who do not comply can be fined up to £500, according to GOV.UK. In Scotland, Wales and Northern Ireland microchipping cats is still optional.

Cats chipped today get a 15-digit chip (ISO standard, also called FDX-B), and every flap in this guide reads those. The differences show up with older chips, which can have 9 or 10 digits, and with some chips from abroad:

• SureFlap: reads 15-digit chips, 9-digit AVID chips and most 10-digit chips. According to the manual, 10-digit numbers starting with 000, 010 or 020 do not work.
• Cat Mate 360: 15-digit ISO chips and AVID chips. Not 10-digit chips or chip numbers containing letters.
• PetSafe Petporte: 15-digit chips only, and not numbers starting with 977 or 98514.
• PetSafe Microchip Cat Flap: 15-digit chips only, according to the Amazon UK listing.

You find the chip number on your vet records, your microchip certificate or a pet passport. If you are not sure which database your cat is on, a vet or rescue centre can scan the chip. For a cat with an unreadable chip, or no chip at all, SureFlap and Cat Mate sell an RFID tag for the collar that the flap learns instead.

What to look for

Curfew mode or timer

A curfew locks the flap at set times, for example from dusk until morning. Owners use it to keep their cat in at night, or on the morning of a vet appointment. On SureFlap flaps, owners report that a curfew still lets the cat come home and only stops it going back out.

The SureFlap Microchip Pet Door has a curfew mode on the door itself. With the Connect versions you set curfew times in the app. The PetSafe Petporte has a night mode and the Cat Mate Elite has a programmable timer. The standard SureFlap Microchip Cat Flap and the Cat Mate 360 have no timer, so you turn the lock by hand.

App and hub: the smart cat flap

A smart cat flap is a microchip flap you control from your phone. At SureFlap these are the Connect models. You get a notification when your cat comes in or goes out, you can lock the flap from the sofa or from holiday, and you can share access with a cat sitter.

For any of that you need the Sure Petcare Hub. It plugs into a spare port on your router with an ethernet cable, so it has to stand somewhere near your router and within reach of the flap. Without the hub, a Connect flap works as an ordinary microchip flap. Check whether the hub is in the box, because the Connect flaps are also sold without it.

An app tells you whether your cat is in or out, never where it is. If you want to see where your cat roams, read our guide to the best GPS tracker for cats.

Size: will your cat fit through?

Look at the flap opening, the narrowest part your cat has to pass through. Measure your cat across the shoulders and compare.

• SureFlap Microchip Cat Flap and DualScan: 142 x 120 mm.
• Cat Mate 360: 145 x 145 mm, for small to medium cats according to the maker.
• PetSafe Petporte: 160 x 160 mm, for cats with shoulders up to 150 mm wide.
• SureFlap Microchip Pet Door (also Connect): 178 x 170 mm, made for large cats and small dogs.

With a Maine Coon, a Norwegian Forest Cat or a hefty tom, go straight for the SureFlap Pet Door. In doubt, pick the larger flap. A cat that has to squeeze through a tight opening may start avoiding it. More on big cats in our Maine Coon guide.

Fitting in a uPVC door, glass or a wall

A timber door or the solid panel of a uPVC back door is the easiest place. You cut a hole using the template in the box and screw the two halves of the frame together. The Cat Mate 360 lines doors up to 85 mm thick without extra parts. For thicker doors and walls every brand sells tunnel extenders, and the Cat Mate needs a wall liner and adapter for walls thicker than about 5 cm (2 in).

Glass is harder. You cannot cut into an existing double-glazed unit yourself. A glazier makes a new sealed unit with a round hole in it, and you fit the flap into that. For the SureFlap Microchip Cat Flap the ideal hole is 212 mm across, and SureFlap sells a mounting adaptor for holes up to 260 mm. The Pet Door needs a hole of about 300 mm and a separate Pet Door mounting adaptor. Several Amazon reviewers had their flap sitting on the worktop for a couple of weeks while the glazier made the new pane, so order the glass first.

Take care with metal doors. Metal near the reader can stop it picking up the chip. PetSafe advises holding the programmed flap against the door and bringing your cat to it before you cut anything. If the lock releases, it should work once fitted.

Batteries

Microchip flaps run on batteries. The SureFlap Cat Flap and the Cat Mate 360 take four AA cells and last up to about a year, according to the makers. The SureFlap Pet Door takes four C cells and lasts up to 12 months, the Connect version up to 6 months because of the radio link to the hub. SureFlap points out that fur on the sensors makes batteries drain faster, so wipe the tunnel now and then. The Petporte comes with a mains power supply.

The best microchip cat flaps

What owners say about the SureFlap Microchip Cat Flap

With more than 22,000 ratings on Amazon UK, this is the best-reviewed flap by a distance. One owner whose vet placed the chip well off-centre on the back of the neck found the flap picked it up every time. Another lasted 14 years with a large cat before parts started breaking, and its replacement fitted straight into the same hole. Most cats learn it within days. One owner got there in two with a dab of butter on the frame, although the click of the latch made the cat jumpy at first. A very nervous rescue cat needed weeks, with the flap left unlocked and treats on the other side. The complaints are about the rare flap that stops recognising a cat, leaving it head-butting the door at night, and a couple of owners of bigger cats who found it a tight fit. A practical tip from a reviewer: download the full manual, because the leaflet in the box is thin.

What owners say about the SureFlap Microchip Pet Door

Owners buy this one mainly for the curfew and the size. A Maine Coon owner whose cat never liked the old cat flap found she walked straight through this one. Another reports that the first set of batteries was still showing full after nearly a year, with one cat and a 10pm to 6am curfew. Several mention it picked up 12-year-old chips in their dogs and cats without trouble. One owner had it recommended by their glazier, who fitted it in a glass door with the mounting adaptor. The click when the lock releases is loud, and cats need a few days to get used to it. One owner of two cats found the magnets too strong and the noise too much, and her cats refused to use it at all.

What owners say about the SureFlap Pet Door Connect

Owners who travel or worry love the app. One locks the door from upstairs as soon as the cat is in for the night and unlocks it at 6am from bed. A pet sitter could check that two cats who rarely show themselves were still coming and going. Reviews are more mixed than for the plain Pet Door, though, and nearly all complaints are about power and connection. Owners report batteries dropping fast, one by 30% in the first week, and one owner says the door lost its curfew settings after a battery change. With the hub 15 feet away through a wooden door, one reviewer had a poor connection, while another runs fine three rooms away on one bar of signal. Sure Petcare's customer service gets a lot of praise, including a video call that ended with a replacement being sent. Use good alkaline batteries and put the hub as close to the door as your router allows.

What owners say about the Cat Mate 360

Most reviews come from owners who were fed up with visiting cats eating the food or spraying. One house with three female cats was being invaded nightly by two or three toms, and the smell stopped once the flap went in. Another owner has had it for three years without reprogramming it once and changes the batteries about once a year. A reviewer with a 4.5 kg shorthair liked the longer flap. Cats do have to come close before it reads the chip, which confuses some at first. On the downside, fitting is as fiddly as with any flap, especially with a tunnel extension, and one owner had two units stop recognising her cat within a few years.

Also worth considering

SureFlap DualScan and Microchip Cat Flap Connect. Same size as the standard SureFlap, but with a reader on both sides, so you can choose per cat who may go out. The answer for a home with an indoor cat and an outdoor cat sharing one flap.

PetSafe Petporte Smart Flap. A 160 x 160 mm opening and a night mode that keeps your cat in after dark without an app. It runs on a mains power supply, so you need a socket near the door. Its chip compatibility is the narrowest in this guide.

PetSafe Microchip Cat Flap. A popular budget flap with a four-way lock that stores up to 40 pets. It only reads 15-digit chips.

Cat Mate Elite with timer. The cheapest way to get a timer on a microchip flap. Its Amazon reviews are clearly weaker than the others here, with some owners reporting that it does not pick up one of their cats.

Microchip cat flaps compared

Figures from Sure Petcare, Closer Pets (Cat Mate) and PetSafe, checked in October 2026.

Has Which? tested microchip cat flaps?

We could not find a Which? test of microchip cat flaps. If you are a member, it is worth a look on which.co.uk in case one has appeared since. Our advice is based on the makers' specifications, thousands of owner reviews on Amazon UK and what you need as a cat owner.

Microchip cat flap or an ordinary one?

An ordinary magnetic cat flap is cheaper and needs no batteries. It also opens for any animal that fits through it. Live on a street with plenty of cats and you soon have a visitor at the food bowl, or a tom marking your sofa. A microchip flap stops that. If an intruder has already sprayed, our guide on getting rid of cat pee smell helps you clear it up. With no other cats nearby, a simple lockable flap is enough.

Making your garden more appealing helps your cat feel at home outdoors as well. See our tips for keeping cats in the garden.

Getting your cat used to the flap

Lots of cats hesitate at a flap that clicks and swings. Register the chip before you fit the flap, by holding it up and letting your cat put its head into the tunnel, so you are not wrestling a cat through a door later. Once it is fitted, prop the flap open for the first few days with tape or a clothes peg, so your cat can walk through without pushing. Put a treat on the other side. When that goes well, let the flap down again. A cat that already used an ordinary flap usually needs a day or two to get used to the click of the latch.

If the flap stops recognising your cat, first fit fresh alkaline batteries and clean any fur off the sensors in the tunnel. If that does not help, clear the memory and register the chip again.

Frequently asked questions