T4 Summary report in QuickBooks
Unfortunately, you can only view reports for the current and previous years in QuickBooks.
Here is one of the customers who faced a problem viewing the previous year's T4 summary:
In my QuickBooks, I am only able to view a T4 Summary report for 2015 and 2016. This makes no sense as I have ones from previous years that I should be able to view.
"I spoke with multiple Quickbooks customer support staff and a manager (who informed me that he knew nothing about Quickbooks, he was just a manager and I would have to speak to support about my issue). These calls took up hours of my time and the issues were never resolved. I was told that I do not have the option to view T4 Summary reports before 2015 and they could not help me."