I want auto fill how do I do it and when will it ask ?

[TonyC11 · Accepted solution]

You need to be registered for My Return for CRA.
Login and find out what 2016 slips CRA has posted for you. Those will be downloaded to you.
As you go to enter your T-slips,you will be asked to AutoFill.

Beware if you have T3 and T5008 slips. These don't lend themselves well,as format is complex.
In case of T5008 there are almost always non entries for Cost Base of the investment.