A crate is refused at the cargo counter for how it is built at least as often as for how big it is. Size is the part owners research. Construction is the part that fails on the day, because the standard is specific in ways that a pet shop label does not tell you.

This page sets out what the IATA container standard actually requires. Sizing is a separate calculation and it is covered in what size crate your pet needs.

What the Container Can Be Made Of

The permitted materials are fiberglass, metal, rigid plastics, welded wire mesh, solid wood or plywood. For an animal traveling in the hold the container has to be rigid. For an animal in the cabin it does not, which is the reason a soft carrier is fine at your feet and useless as a shipping container.

The roof must be solid. Ventilation openings and welded wire mesh are allowed across the whole of it, provided they do not reduce the structural integrity of the container. A crate with an open or mesh top that is not built to take weight is not compliant, and the reason is that other freight may sit above it.

Ventilation: the 16% Rule

This is the requirement most often failed by crates sold as airline approved, and it is a number rather than an impression.

Ventilation must be provided on all four sides of the container, and the total ventilated area must be at least 16% of the total surface of those four sides. Most domestic kennels sold in North America have a barred door and vents along the upper sides only, which passes for a car journey and does not pass here.

The placement is specified as well. Openings on the sides and the back sit over the upper two-thirds of the container, with additional ventilation permitted on the lower third of the front and back. So adding holes low down on the sides does not fix a crate that fails the test.

The Door Is Where Crates Fail

Three things about the door, and each has caused a refusal.

  • It must form the whole of one end of the container. A hatch or a partial opening is not a door.
  • It may be sliding or hinged, but the locking pins have to engage the container by at least 1.6 cm. A pin that seats a few millimeters is the single most common construction failure on a molded plastic kennel.
  • On a plastic container the hinges and locking pins must be metal of sufficient thickness, and the door should be further secured with additional removable fasteners, cable ties in the four corners being the usual method.

That last point is worth reading twice, because it is the cheapest compliance step in the whole process and the one owners skip. Four cable ties, applied at the four corners of the door, and they must be removable rather than permanent so the animal can be released quickly.

Water, Bedding and What Goes Inside

  • A water container must be present and fixed inside the shipping container, with outside access for filling. Someone has to be able to top it up without opening the door.
  • The water container must be open on its top surface so the animal has unrestricted access to it. A closed bottle-style dispenser does not satisfy this.
  • Absorbent bedding suitable for the species must be provided. That is a requirement rather than a comfort measure, and it is also why the height calculation adds the depth of the bedding to the animal’s standing height.

Labels, and the Wheels Nobody Thinks About

Two markings are required and one component has to be disabled.

  • A green Live Animals label goes on the container.
  • This Way Up labels go on at least two opposite sides.
  • Marking the animal’s name on the container is recommended rather than required, and it is worth doing.
  • If the container has wheels, they must be removed or rendered inoperable. A wheeled kennel that rolls on a moving aircraft is the reason for the rule, and taping the wheels is not the same as removing them.

The labels matter more than they look. A crate that reaches a ramp without a Live Animals label is a box, and it will be handled like one.

Cabin Carriers Are a Different Standard

Everything above describes a container for the hold. A cabin carrier is judged differently and the difference is worth stating so nobody buys the wrong one.

For an animal in the cabin the container does not have to be rigid, which is why soft-sided carriers are normal there and why some airlines now require them. Air Canada has done so since 1 June 2025. What governs a cabin carrier instead is the airline’s own maximum dimensions and the under-seat space on the specific aircraft, which our guide to US airline pet policies sets out.

So the two questions are genuinely separate. A carrier that meets an airline’s cabin rules is not a shipping container, and a compliant shipping container will not fit under a seat.

Frequently asked questions

Is an airline approved crate automatically compliant?

Not reliably. The phrase is marketing rather than a certification. The tests are the ones on this page: rigid construction with a solid roof, ventilation on all four sides totalling at least 16% of those four surfaces, a door forming the whole of one end with metal hinges and locking pins engaging at least 1.6 cm, an externally fillable water container, absorbent bedding, and no working wheels. Check the crate against those rather than against the label.

Do I really need to cable tie the door?

For a plastic container, yes. The standard asks for the door to be further secured with additional removable fasteners, and cable ties at the four corners are the usual method. They must be removable so the animal can be released quickly, which means cutting them has to be possible without dismantling the crate.

Can I use a wire crate?

Welded wire mesh is a permitted material, so a properly built mesh container can comply. A collapsible wire home crate generally will not, because it is not rigid in the way the standard means and its door and fastenings are not built to it.

Why does the water bowl have to be reachable from outside?

So the animal can be given water during a delay without the door being opened. A bowl that requires opening the container is a bowl nobody will fill, and it is one of the checks made at acceptance.

Does my dog need a bigger crate than the rules require?

No, and a larger crate costs money because cargo is priced on the outside dimensions. The requirement is that the animal can stand and sit erect, turn around normally and lie in a natural position. Beyond that, buy to the formula in our crate sizing guide.

Sources

  • IATA, Container Requirements 1 for dogs and cats. Permitted materials, the solid roof, ventilation on all four sides at a minimum of 16% of those surfaces and its placement, the door forming the whole of one end, the 1.6 cm locking pin engagement, metal hinges and pins on plastic containers with additional removable fasteners, the externally fillable open water container, absorbent bedding, wheels removed or rendered inoperable, and the Live Animals and This Way Up labels.
  • IATA, Traveler’s Pet Corner. That the container does not have to be rigid for cabin travel.

Last updated 8 September 2026