Some things like alcohol are technically taxed when crossing provincial lines, but trays not well enforced. Alcohol regulations are different, many provinces only allow sales through a provincial liquor board.

Lots of other things are restricted because standards in one province are incompatible with others.

I think some professional organizations have different educational requirements.

It’s kinda like a country as a fediverse lmao /jk

Here’s a good article:

https://www.cbc.ca/news/business/interprovincial-trade-barriers-4-ways-1.7453530