Checking in a bag
Airlines set the rules for how many bags you may check in and for possible related charges. The rules vary according to frequent flyer status, the product you have purchased and the route upon which you fly.
Your bag should weigh less than 23KG/50LBS. This is an international regulation set for the health and safety of airport workers who have to lift hundreds of bags daily. If your bag weighs more than this, you may be asked to repack, or have it labeled as "heavy luggage". The maximum weight however is 32KG/70LBS in the EU and the US. Some airlines impose lower limits. Refer to the airline website and your conditions of carriage.
Airlines set cabin baggage rules in order to comply with space at disposal in the aircraft and as a matter of commercial policy.
Carry-on baggage must be stowed in the cabin, which limits baggage to a size, weight and shape to fit under a passenger seat, or in a storage compartment. Some aircraft have very limited cabin baggage space, and even on larger aircraft, your bag may be taken from you. .
If you are changing carriers during your journey you may be asked to check some of your cabin baggage as each airline will apply their own policy to the their own flights. It is worth checking with your airline(s) before you travel as to their policies.
So, what does IATA do?
Airlines set their own baggage rules and IATA plays no role in this activity. Instead, IATA is focused on developing best practices for baggage operations. As a result of joint efforts in coordination with our member airlines, baggage mishandling was reduced from 18 bags per 1000 passengers to under 9 between 2008 and 2012 and to 7 by mid-2014.
Why it's essential your bag is identifiable
Occurrences of mishandled baggage have drastically dropped in the past years. And lost baggage are generally the consequence of the baggage label having detached from the bag. To allow identification of your bag in all situations, make sure to have your name and telephone number appear outside of your bag and a copy of your travel itinerary inside your bag. When there is no other way to identify your luggage, the airline will have to break it open and this identification piece will be crucial to returning your belongings.
Dangerous goods and baggage
Some governments have directed that for safety reasons, all knives, sharp objects or cutting implements of any kind and of any length, whether of metal or other material, and some sporting goods must be packed in checked baggage. They cannot be carried in the cabin baggage nor on your person.
These items include (but are not limited to) knives (including household cutlery) and knife-like objects, box cutters, corkscrews, straight razors, metal nail files, scissors of any kind and of any length, dangerous goods (hazardous materials (unless approved)), tradesmen's tools, hypodermic needles (unless required for medical reasons), knitting needles, other sharp pointed/penetrating objects and sporting goods such as bats, bows and arrows, cues, darts, golf clubs and sling shots (catapults), martial arts devices, real/toy/replica weapons (whether plastic or metal). These articles are likely to be removed and not returned.
If you require the use of medical syringes in flight, such as for insulin, you need documented proof of the medical need and ensure that the material is professionally packed and labelled. If it is not, the medication is likely to be removed.
Some items cannot be carried in checked baggage – for instance gas canisters, lighters, fireworks. If you are concerned that something that you wish to pack may not be allowed, check with your airline. Items that are considered to be too dangerous for checked baggage will be removed and probably not returned to you.
Check with your travel agent or directly with the airline concerned.