Is my business liable for PAYE as soon as I register?

I registered my SME for PAYE in December 2015. When do I become eligible to start paying PAYE? I'm the only employee and my salary is tax deductible?

You probably should have paid PAYE on January salary which would have been due 7 Feb 2016. Sometimes however, there can be a one month delay between registration and when PAYE becomes due so it may have been due only 7 March 2016. Do check with SARS on 0800 007 277 ASAP as they will slap on a 10% PAYE penalty if payment is late. You could also run a EMP201 Statement of Account to see if this has occurred yet.