Self-employed

When you issue yourself a T4, meaning that you are an employee of the company, they expect to receive regular payroll source deductions, rather than one lump sum.  They will consider that you are a) not sending in applicable source deductions on a monthly basis which is the least number of pay periods available, or b) just paying yourself arbitrarily an amount intended to reduce any corporate tax to nil.  Both scenarios irritate CRA.  You would need to send in several nil payroll returns and then one large one, assuming that you have asked CRA to open a payroll account.  They don't do that automatically.  Since this is your first year, and since filing a T5 is little different from filing a T4, I would recommend that approach.  I also suggest that you take time to talk to an accountant about your corporate filing requirements.  It will save you much grief.  When software refuses to do what you want, there may be a good reason for it.