Depends mainly on the battery and actual battery size. In Australia
(and most countries will be the same as they operate under ICAO regulations), all 406 beacons use Lithium batteries which are classified as Dangerous Goods. Doesn't mean they can't be carried, just means they have to be declared as such. Whether or not they will be accepted depends on the packing and size. For instance, you may bhe able to ship one battery but not (say) 10 of a certain size. MUST be declared otherwise very bad. There are some very small 406 PLB's available that are classified as "NONHAZMAT" which can be carried as checked luggage without any problems.
Older 121.5 / 243 beacons normally had akaline batteries, not sure on the current
regs for them.
Always disconnect the battery (if possible) or tape the switch so it CAN'T be operated.