Microchip Pet Doors (2026): Which Chips They Read, Batteries, and Keeping Strays Out

A microchip pet door unlocks only for the pets you have paired with it, which keeps a neighbor's cat, a raccoon or a stray from walking into your kitchen. For most cats, buy the PetSafe Microchip Cat Door if your cat has a 15-digit chip, or the PetSafe SmartDoor Connected Medium if the chip is an older 9 or 10-digit type or you want app control. SureFlap makes the best-known microchip cat flaps, and says they read all common chips, but on Amazon they were sold only by third-party sellers when we checked. For a dog over 25 lb, no door here reads microchips, and a collar-key door is the answer.

How we chose: we did not install these doors; we compared what SureFlap and PetSafe publish about chips, batteries and installation, and gave cards only to doors sold by Amazon.com or the brand's own store on September 28, 2026.

Five selective pet doors side by side

Prices are Amazon's, as of the time shown, and subject to change. Details

PetSafe's figures come from its Microchip Cat Door page and SmartDoor Connected page; SureFlap's from its Microchip Cat Flap and Microchip Pet Door pages. The Electronic Pet Door figures are from its Amazon listing.

Check your pet's chip before you cut a hole

The door reads the same chip a vet or shelter scans, so the first question is which chip your pet has. The AVMA's microchip page explains why that varies: chips "can differ in both the radiofrequency at which they operate and the length of their identification numbers," and there is "no single U.S. standard." The AVMA supports chips that meet ISO standards, which "use a unique 15-digit identification number and operate at a radiofrequency of 134.2 kilohertz (kHz)."

That is the chip the PetSafe Microchip Cat Door is built around. PetSafe says it "works with 15-digit microchip numbers and can read all FDX-B, 977 and 985 microchips," and lists Datamars/PetLink, HomeAgain, AVID, 24PetWatch, AKC Reunite and Banfield as compatible brands. Asked about a specific older chip, PetSafe's answer on the same page was that the door "is compatible with most 15 digit microchips," and to check that your pet's number has 15 digits.

Older U.S. chips are often shorter. PetSafe says only the Medium SmartDoor Connected pairs with chips, and that it reads "FDX-B/15 Digit, FDX-A/10 Digit, AVID H, and AVID Encrypted/9 or 15 Digit microchips." SureFlap says its doors work with "all common identification microchips," and it runs an online compatibility checker where you can enter your pet's chip number before buying.

Your vet can read the number from the chip at the next visit, or it may be on your adoption papers. If the door will not read the chip, both makers sell a collar key or tag instead.

The AVMA adds one point that matters more than the door: "A microchip is only as effective as the information linked to it." Register the chip in your name and keep the phone number current. Our collar and ID tag guide covers why the AVMA still wants a tag on the collar.

Batteries and how long they last

Every door here runs on batteries, and a door with flat batteries is either stuck locked or stuck open, depending on the model. What the makers say:

• SureFlap Microchip Cat Flap and DualScan: 4 AA batteries, "up to 12 months battery life," per SureFlap. The manual asks for "good quality AA 1.5V alkaline batteries" and says the light flashes red every 5 seconds when they run low.
• SureFlap Microchip Pet Door: 4 C batteries, up to 12 months, with a low-battery light. SureFlap says the door keeps its stored pets when the batteries are out.
• PetSafe Microchip Cat Door: 4 AA alkaline batteries (LR6), per its manual, with a red light every 10 seconds when they are low. PetSafe does not give a battery life, and in a reply on its product page says it does "not recommend rechargeable batteries" for this door.
• PetSafe SmartDoor Connected: 4 C alkaline batteries for the Medium, 4 D for the Large, or a plug-in power adaptor for either.
• PetSafe Electronic Pet Door: 4 D batteries, per the listing.

SureFlap also says to clean the tunnel sensors every 2 to 3 months, because dirt on them "can lead to battery drainage." Keep a spare set of the right batteries in the drawer.

Keeping strays out, and letting your own pets out

A microchip door is selective, not a vault. Both makers say so in writing. PetSafe's manual says "it is not possible to fully guarantee the exclusion of all other animals in all circumstances," and SureFlap's uses nearly the same words. SureFlap adds that its locks "are not a security device."

The bigger design point is which side reads the chip. On the SureFlap Microchip Cat Flap, "the microchip reader is located on the outside of the cat door only," so "any animal can exit." PetSafe says the same of its cat door: it reads "in one direction," which keeps unpaired animals from coming in "but allowing any cat indoors to go outside." If you have one cat that must stay in and one that goes out, a one-way reader cannot tell them apart.

That is what SureFlap's DualScan is for: SureFlap says it lets you "set exit permissions for each pet to keep specific pets indoors." The PetSafe SmartDoor Connected also offers "selective entry and exit" per pet, with schedules in its app.

For nights, all of these have manual locks. PetSafe's cat door has four settings: locked, unlocked, in only and out only. SureFlap's cat flaps have a manual lock and an in-only setting, and its Microchip Pet Door adds a curfew mode that locks and unlocks at set times.

Key point: if the goal is keeping your own cat indoors at night, set the door to in only before dusk. The cat can come home but not go back out, and nothing without a paired chip can follow it in.

No chip, or a chip the door cannot read

Both makers sell a collar-worn key. PetSafe's Microchip Cat Door Key is for "cats with incompatible microchips," per its listing (it was not in stock on Amazon when we checked). SureFlap sells RFID collar tags and includes one with the Microchip Pet Door.

A collar tag brings a collar-safety question. SureFlap's manual says that if you use its tag, "it should be used with a safety collar which incorporates a breakaway buckle (cats only)." A cat that wears a collar outdoors can snag it, and a breakaway buckle lets go.

For a dog, a collar key is the normal way these doors work. PetSafe's SmartDoor Connected comes with one key, and its Electronic Pet Door "works with the waterproof Electronic Pet Door Key worn on your pet's collar." Our GPS tracker guide covers what else can hang on a collar, by weight.

Door, wall or glass: what each install needs

Check the thing you plan to cut before you order.

• PetSafe Microchip Cat Door: fits "wood, PVC, and uPVC" doors as is. For glass, metal or brick you need the Microchip Installation Adaptor, and for walls a tunnel extension, both sold separately. Its manual allows single-glazed glass with a 215 mm (8 7/16 in) round hole cut by a glazier, and warns that toughened glass and double-glazed units cannot be cut after they are made. It also says the door works only between -13°F and 131°F.
• SureFlap Microchip Cat Flap: installs in doors, walls or glass, per SureFlap, with accessories for windows and walls. Glass needs an 8 3/8 in round hole (up to 10 1/4 in), and a door needs a 6 1/2 x 6 3/4 in cut-out.
• PetSafe SmartDoor Connected: the Medium goes into a door with little or no metal up to 2 1/4 in thick as is, and into multi-pane glass up to 1 3/4 in thick with an adaptor and a glazier. Walls and metal doors need extra parts, per PetSafe's chart.
• PetSafe Electronic Pet Door: door installation; a wall kit is sold separately, per the listing.

Measure your pet too. PetSafe's manual says a cat's belly height is usually 100 to 150 mm (about 4 to 6 in) and that the hole's bottom edge sits at that line. SureFlap says its cat flap is only for cats that fit through its 5 5/8 x 4 3/4 in opening; a large cat may need the Pet Door's bigger 7.5 x 6 11/16 in flap. PetSafe's SmartDoor Medium is for pets up to 25 lb, and its Large up to 100 lb.

Which to buy

• Cat with a 15-digit chip, one-way control is enough: the PetSafe Microchip Cat Door.
• Cat or small dog with a 9 or 10-digit chip, or you want app locks and schedules: the PetSafe SmartDoor Connected Medium.
• One cat stays in, another goes out: SureFlap's DualScan, from a seller you trust (it was third-party only on Amazon when we checked), or the SmartDoor's per-pet exit settings.
• Dog over 25 lb: a collar-key door such as the PetSafe Electronic Pet Door, Large.

An outdoor cat still needs its flea and tick prevention and a carrier for the vet; see our new kitten checklist for the rest. If you are wondering whether letting your cat out is right for its health, ask your vet (more on that).

Seller and recall check

Every SureFlap door we found on Amazon on September 28, 2026 was sold by a third-party seller (SparkleFront, Trading 247, brinleys bargains and others), not by Amazon.com or a SureFlap store, so SureFlap has no cards here. SureFlap's microchip pet feeder, a different product, was sold by Amazon.com; our automatic feeder guide covers feeders. Buy a SureFlap door from SureFlap or a retailer it lists.

We found no CPSC recall of a PetSafe or SureFlap pet door in the CPSC recall database, and neither brand appears on our pet product recall page as of September 28, 2026.

Frequently Asked Questions

Will a microchip cat door work with my cat's chip?

Probably, if it is a 15-digit chip; check before you buy. PetSafe's Microchip Cat Door reads 15-digit FDX-B chips, its SmartDoor Connected Medium also reads 10-digit FDX-A and 9 or 15-digit AVID chips, and SureFlap says its doors read all common identification chips.

How long do the batteries last in a microchip cat flap?

SureFlap says up to 12 months on 4 AA batteries for its cat flaps and 4 C batteries for its Pet Door. PetSafe does not publish a battery life for its Microchip Cat Door, which takes 4 AA alkaline batteries.

Can other cats get in through a microchip cat door?

The door stays locked for animals without a paired chip or key, but both makers say they cannot guarantee keeping out every animal. Most models read only from the outside, so anything already inside can leave.

Is there a microchip dog door for large dogs?

Not among these. PetSafe says only its Medium SmartDoor, for pets up to 25 lb, pairs with microchips; its Large doors, for dogs up to 100 lb, open with a collar key.

Can I keep one cat in and let another out?

Yes, with a door that reads in both directions. SureFlap's DualScan sets exit permission per pet, and PetSafe's SmartDoor Connected offers per-pet entry and exit schedules.

---

PetProofLab is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com. We did not install or test these doors; chip types, batteries and sizes are the makers' own, from their sites, manuals and listings.