Youre an accountant preparing tax returns for your clients. One of your clients has received a letter from CRA indicating their tax return has been reassessed. Your client does not agree with CRA's decision. What can the taxpayer do and when must they do it?

- 2017 Tax Return was Reassessed

- Date of Original Notice of Assessment for 2017 Return is May 10, 2018

- Date of New Notice of Reassessment for 2017 Return is Oct 1, 2018

- The taxpayer has income from a sole proprietorship