When do you have to tell the CRA that your marital status has changed?
If you recently got married, divorced, became widowed, or entered into a common-law partnership, you must tell the CRA about the change in marital status by the end of the month after the month your status changed. For example, if your status changes in March, you must tell the CRA by the end of April.
If you have become separated, do not notify us until you have been separated for at least 90 days