Just Called my BANK
OK if you buy a Candian company in US like CXRX in your TFSA account, then there is NO
witholding tax of 15%.
As long as the company is based in Canada, there is NO TAX of this kind.
For US stocks below, like AAPL
There is never a witholding tax in RRSP accounts.
There is though on margin ,cash and TFSA accounts.