Question: how many years can you go back to amend a gst return in canada?
Answer: First and foremost, if you need to amend your tax return, do not file another return for that year. You must wait to receive your Notice of Assessment before making any changes to your tax return. Amendments can be made for 10 previous years, so if you are filing this year's (2019), you can only amend back to 2009.