Am I allowed to send Christmas crackers by courier?
We're afraid not.
Seemingly all courier companies prohibit the sending of items that include explosives via their network, and that's certainly true of Parcelforce, DHL and DX. Along with Christmas crackers, other items in this category that you cannot send by courier are:
chemical compounds that can be mixed to produce a pyrotechnic effect;
Christmas cracker snaps,
It should be fairly evident why courier companies would not want explosive or flammable materials being pass through their network. However, just to be clear, they pose not only a danger to the courier staff but could potential damage other people's parcels travelling through the systems at the same time.