At some stage all of us get on the plane, by choice or not.

Whether you have to visit your mum’s second cousin in Toowoomba or you’re planning a fancy honeymoon in Rome, the process is the same; you buy a ticket, pack your bags, check in for the flight and get on board.

And after a few hours on a plane, you can’t wait to just get off, get your bag, get in a taxi and finally be done with the whole flying thing.

But have you ever arrived at your final destination and not found your bag on the carousel?

It can be very stressful, but around two million bags are reported missing upon arrival every year. For comparison, the population of Perth is two million people— imagine that every resident of Perth just lost their luggage.

But what are the main reasons bags get missed?

Linda Gadanec, a Mishandled Luggage Department trainer at Swissport, says that most of the time it comes down to a simple human error.

“[It can be] incorrect tagging at check-in, tags coming off of bags, if it’s something like a duffel bag and the tag was looped through both the handles and then the handles fall apart and the tag comes off,” she told upstart.

“[Or] going through the baggage belts and ending up at the wrong place for collection to be loaded on to an appropriate aircraft, if the time is too short between the connecting flights for the bags to be taken from one aircraft to another.”

While these check-in errors are common, they are not the only potential issue. Bjorn Jonkman, a Ramp Duty Manager at Swissport, says there can also be a complicated security screening process that doesn’t allow ramp staff to load a bag onto a plane.

He says international flights pose the biggest risk, as they have three levels of security for bags to pass through.

“Level one is x-ray and bomb residue check, level two is a random manual check of each bag and level three is also a manual check with metal detectors. So if a bag is selected to go to level two screening, it might take up to 40 minutes before that bag get to the right lateral,” he told upstart.

“Often at that time the flight is already closed, and this bag gets on a reject belt and misses its flight.”

If that does happen, the airlines will not just leave you alone. Each airline has a baggage services desk, and staff there will be able to help you find the location of your bag.

“If the bag missed a flight when the passenger arrives at their destination they do a missing bag report, and it is a ground handler’s responsibility to check all the ports they have flown through,” Jonkman said.

“[They would] see if there any on-handed or tagless bags and request them to be rushed on the next available flight so the bag can be re-united with the owner.”

The process can seem more complicated that it is. Basically, if the bag is tagged correctly, it will be found by the time the flight lands at its final destination.

However, it is slightly more complicated if the bag gets damaged. Jonkman says that bags can get broken during the plane loading.

“Bags get damaged during the handling in the aircraft because you have to stack them. You have to fit a hundred bags into a small compartment, so you’re not gentle with it unless they have a ‘fragile’ tag. They have to fit in,” he said.

Even in this situation, the airlines still carry responsibility for your bag. They will make sure it is fixed and replaced, or they will fully or partially reimburse the cost.

Travelling on its own can be stressful, and dealing with these complications doesn’t make the process any easier, but every airline has friendly staff who are happy to help resolve any issues. However, passengers should always try to prevent these problems to the best of their ability.

Packing your suitcases correctly will help you to avoid unnecessary stress when you arrive. Gadanec says that avoiding having fragile, high-value or dangerous items in your checked bags is a good start, and that passengers should always plan for the worst-case scenario.

“Expect the bag not to get there if you are travelling with multiple connecting flights. Always in your carry-on have the bare essentials, because that’s what carry-on is for,” she said.

“It is to have your essentials to get you through a couple of days until your bag is reunited with you if it missed its connections.”

Yulia Fokina is a second year Bachelor of Media and Communications (Journalism) student at La Trobe. You can follow her on Twitter @Yulia__Fokina.