How and when do you file your HST returns with CRA? Depending on your businesses gross annual income, is how often you have to file. If you make over six million you have to file monthly, if you make between one and a half and six million you have to file quarterly, if make less than one and a half million, you file annually prior to June 30 . Payment isd due at the end of the fourth month after your year end. For example, December 31 year end means payment is due April 30. Filing Harmonized Sales Tax (HST) can be done online, on the Canada Revenue (CRA) website. If you need assistance feel free to contact me.