If you recently filed your tax return, you might not see your current year's Notice of Assessment when you sign in to your CRA My Account or MyCRA. It can take up to two weeks for the CRA to assess your return if you submitted to CRA’s NETFILE service and anywhere from 4 to 6 weeks if you printed and mailed your return.
If you filed near or after the tax deadline of April 30th, it can take even longer for the CRA to assess your return, sometimes as long as 8 weeks.