Thanks for reaching out to us here. QuickBooks is a versatile program that simplifies your payroll process. I'll be glad to share more info and steer you in the right direction.
In order to download a T4 from a previous year, please check out the steps below:
Select Payroll, then select Payroll tax.
Select the Filing tab.
Scroll down to the Done section.
Select Download XML from the dropdown menu.
For steps on submitting the T4, I recommend checking out this helpful article here. Feel free to ask other questions. I'll be one message away in case you need anything else.