I will assume you know why you need to make such an election for your American Roth IRA. If you don't know, research it. I contacted CRA via mail recently and got the confirmation as below: We received your letter dated xxx in regards to filing an election for a Roth IRA. You should follow the steps as in the Technical News No. 43 where it says: How Should an Election be made? Technical News No 43 is available https://www.canada.ca/en/revenue-agency/services/forms-publications/publications/itnews-43.html Competent Authority Services Division is the branch of CRA which handles this issue. You can contact them for more informationhttps://www.canada.ca/en/revenue-agency/services/tax/international-non-residents/competent-authority-services/who-we-contact-us.html. I hope my information be useful to future readers.