Start with HRI–there are 2 really good pieces that address the legal requirements for payroll record keeping
https://hrinsider.ca/what-payroll-records-does-the-law-require/
https://hrinsider.ca/payroll-recordkeeping-requirements-across-canada/
Other resources:
Ontario MOL ESA guidelines https://www.ontario.ca/document/your-guide-employment-standards-act-0/record-keeping
Canadian Fed Govt. file:///C:/Users/glenn/Downloads/records_(2)%20(1).pdf
Good resources on electronic record keeping https://www.mtroyal.ca/rim/ElectronicRecords/index.htm
Hope this helps. Glenn
