Please contact the Canada Revenue Agency (CRA) and confirm which address you should have sent your tax return to. If you sent it to the wrong address, then the CRA can advise you on what to do. If you are in Canada or the United States, you can call the CRA at 1-800-959-8281. If you are elsewhere, you can call 613-940-8495. This CRA page, “Contact the Canada Revenue Agency”, has more ways to contact the CRA.