The deadline this year is April 30, 2020. Late filing penalties and interest begin May 1, 2020, and interest compounds monthly, so please come in as early as possible to avoid fines. April 30th is the filing deadline. If you are self-employed, you can file by June 15th, however, if you owe taxes, they must be paid by April 30th. If you are self-employed, you can estimate your taxes and pay that amount by April 30th and settle any outstanding balance by June 15th. These same deadlines apply if you are an HST Registrant. Interest on unpaid balances begins May 1st.