I just went through I labor pains of getting a business number and GST number for opening an online store. I live in Alberta and just thought I'd post the steps to get a BN#, GST#, and setting up business name or trade name for your company. Here is the link for the government of canada website to download the form for the BN#, and GST#.  http://www.cra-arc.gc.ca/tx/bsnss/tpcs/bn-ne/rgstr/cmpltng/menu-eng.html or what I found to be easier is just to call them. 1-800-959-5525 If you call and set it up yourself its free. Other wise if you go through a third party it costs money.

To register your trade name or company name as a sole proprieter you have to go through a third party registration agent. Same place you go when you have to renew your car licsense plates every year. They will charge you any where from 30-50 dallors for the service, and the government charges another 35 dallors on top of that. If you happen to be a member of AMA road side assistance. They will do it for you and it cost just a flat fee of 48 dallors. I got my company name registered throught AMA.

Now I can't speak for the rest of Canada, but I live in the county of strathcona, and I had to get a development permit from them to start an online home business, and that costs 250.00 dallors.

I hope that helps someone.