I have noticed several changes for the Ontario tax calculation and I would like to share them with you: 1) Ontario basic sales tax credit $100 Before: many of you know that you are over 16 and you have no income, you will get a refund of $100 (which was known as Ontario basic sales tax credit when you file a tax return Now: the Ontario basic sales tax credit is now incorporated with GST/HST refund (the cheque that government issue to you every quarter). In other words, there is no more $100 Ontario basic sales tax credit. Since you have to be 18 years old in order to receive GST/HST refund, you do not need to file a tax return for those under 18....(you will get nothing). 2) Children's Activity Tax Credit (refundable) Federal tax return always have fitness tax credit (up to $500) and Ontario activity tax credit (refundable) is the maximum of 10% of $500. However, Ontario fitness tax credit includes activities such as piano lessons, Instruction in music, dramatic arts, dance and visual arts etc (which is not considered as fitness activities under Federal). If you have not maximized your $500 federal fitness credit, don't forget to include those non-fitness activity under Ontario return.