Forgetting to change your marital status before tax time could be a costly mistake. As a single person, you may qualify for tax benefits such as GST/HST or the Canada Child Tax Benefit that you may not be eligible for with a combined marriage income. If you receive these benefits when you are not entitled to, you will likely be asked to repay them. It’s in your best interest to make sure your marital status is up-to-date with the CRA.