Can you deduct previous year's fees for tax return with personal income only (T4 income only)?

No.  Canada Revenue says:  You can only claim these fees if they are:

 fees to have someone complete your return, but only if: 

  you have income from a business or property;

• accounting is a usual part of the operations of your business or property; and
• you did not use the amounts claimed to reduce the business or property income you reported (see Interpretation Bulletin IT-99, Legal and Accounting Fees