Short answer: TSA sets no size limit for pet carriers and does not certify them. At the checkpoint TSA requires the pet to be lifted out and the empty carrier to pass through the X-ray. The limit that actually decides cabin fit is your airline’s under-seat allowance — and for animals travelling as cargo, container size comes from the IATA Live Animals Regulations: length = A + ½B, width = C × 2, height = D + bedding, with 10% added for snub-nosed breeds.
What TSA actually requires at the checkpoint
- Small pets are allowed through the checkpoint: the TSA page for small pets states the pet must be removed from the carrying case and the case placed through the X-ray machine.
- A pet is never placed inside the X-ray tunnel — the checkpoint X-ray screens carry-on property, not animals. See TSA’s tips for travelling with small pets.
- Carry the pet through the walk-through metal detector, or walk it through on a leash; the officer may swab the owner’s hands for explosive trace detection.
- If your cat struggles when lifted out, you can request a private screening room while it stays inside the carrier.
Note what is not in that list: no carrier dimension, no frame requirement, no approval mark.
So who sets the size limit? Your airline
Under-seat footprints, cabin weight limits, species and route rules are set airline by airline and aircraft by aircraft, and they change. That is why “TSA approved pet carrier” and “IATA certified pet carrier” are meaningless claims: IATA states plainly that it does not certify, approve, endorse or sell any particular pet container manufacturer, and TSA does not approve carriers either. What you can verify instead is the carrier’s outside dimensions against your airline’s published under-seat size, plus whether the frame compresses slightly to clear a sizer without collapsing on the animal. Our airline-approved carriers size and safety guide covers how to compare those numbers.
The IATA container formula for cargo — the numbers that do exist
For animals travelling as cargo or checked baggage, IATA Live Animals Regulations container requirements define both the dimensions and the construction:
- Container length = A + ½B, width = C × 2, height = D + bedding, where A = nose to base of tail, B = ground to elbow, C = shoulder width, D = standing height to head or ear tip.
- Snub-nosed (brachycephalic) breeds require a container 10% larger.
- Ventilation openings: maximum 25 × 25 mm for dogs and 19 × 19 mm for cats.
- Two adult animals of comparable size, up to 14 kg each, may share one container; animals over 14 kg must be crated individually.
- Animals must be at least eight weeks old and fully weaned before air travel.
Airline rules sit on top of these, and country import rules sit on top of both — our IATA / USDA / EU compliance matrix maps which rule applies where.
How we build against these rules
Our airline-approved range currently lists 23 soft-sided models built to IATA under-seat footprints, with leak-proof bottoms, mesh ventilation and removable washable pads. OEM orders start at 50 pcs (100 pcs for ODM design changes), samples run 7-15 days, bulk production 30-45 days, every batch passes four-stage in-house QC at AQL 2.5, and REACH / RoHS documents plus IATA size-verification notes ship with the order — from a 2,600 m² factory running 18 production lines at 80,000+ pcs per month. Custom under-seat dimensions for a specific airline or market are supported. See the airline-approved pet carriers or request a quote.
Frequently asked questions
Does TSA require a specific pet carrier size?
No. TSA publishes no dimension rule or approval scheme for pet carriers. Its requirement is procedural: the pet comes out of the carrier at the checkpoint and the empty carrier goes through the X-ray. Size limits are set by the airline you fly with.
How do I size a carrier for my cat or dog?
Measure A, B, C and D as defined above and apply the IATA formula for cargo, or for cabin travel compare the carrier’s outside dimensions with the airline’s under-seat numbers. Our step-by-step guide is how to measure your pet for a carrier.
Is “IATA certified pet carrier” a real certification?
No. IATA states it does not certify, approve or endorse any container manufacturer or brand, and it does not sell carriers. What you can ask a factory for instead: the dimension sheet of the model, the frame and fabric spec, and how the model was sized against the airline footprint you need.
Can you produce a carrier to a specific airline’s under-seat size?
Yes — under-seat dimensions, fabric grades, ventilation panel sizes and hardware are all tooled in-house, from 50 pcs for OEM branding or 100 pcs for a design change. Samples are ready in 7-15 days and bulk production runs 30-45 days after approval.
Do your carriers ship with compliance documentation?
Yes. Shipments carry REACH and RoHS documentation plus IATA size-verification notes, and each batch is backed by our four-stage QC record (incoming materials, in-line checks, 100% final inspection, AQL 2.5 pre-shipment).