Luggage straps can be used on checked and carry-on suitcases, as long as the straps can be taken off by the TSA agents. For instance, there are some straps available with combination locks. You should make sure that these locks are TSA-approved, which means that the TSA agents can open them with a unique key.
Are luggage straps useful?
A suitcase strap will keep the bag closed and the contents intact. Colorful straps also make it easier to spot your bag on the carousel when you arrive. Some brands add extra security with a TSA-approved lock and identification tag.
Can you add a luggage strap to a backpack?
Get An Add-On Strap
Elastic add-a-bag straps are great for big and bulky backpacks mostly because of the adjustability. You don't need to worry whether the strap is big enough to go over your backpack if it's elastic and it's very easy to set up and use. Another type of add-a-bag straps is the short buckled strap.