Hi folks,
I am not a pro in bonsai making, but I used to make it during my leisure time. My mom has a nursery in Toronto. One of her regular customers asked her to ship a bonsai to Hamilton. For the most part, clients visit our nursery and purchase whatever they like, this is the first occasion when somebody is requesting that we send a bonsai. Since he is a regular customer of us, we have to do our best to reach to him securely. We were thinking to use the moving boxes that we use for storing things for the transportation . Hope it will be safe. When I searched online for the tips, I have found that the base of the bonsai is secured with the newspaper and tied with tape and again secured both the top and base of the bonsai together. Would it be advisable for me to wrap the pot in damp paper towels so as to get a moist feel to the plant? I thought to add packing peanuts too. Hope this works. Any insights regarding this are greatly welcome.

Cello-wrap the pot, so no substrate can fall out. Then wire the pot to a piece of pliewood, the size of the bottom of the box. Place the thing in the box. Wire the pliewood to the box. Put wooden struts in the upright corners of the box. This way, the plant is free in the box, but cannot move, and the box cannot be compressed when someone puts another box on top.
Then fill the box up.

The tree should be fine for 1-3 days in a box, assuming it was well-watered, and the pot has been cello-wrapped.

www.bonsai4me.com/AdvTech/ATPostingBonsai.htm
Some pictures to accompany LB´s advices
I sold one penjing few weeks ago, wrapped like that, sent it via courier, everything arrived to buyer perfectly safe, delivered next day.
But as you can read on bonsai4me, once properly wrapped, it should be ok for some 5 days no problem