If you get divorced in the middle of the year, in Canada, your first task is to notify the CRA. They will be able to advise you about how to file your tax return for that year and the next one. If you pay spousal or child support, you may be able to claim for those. But, usually, will no longer qualify for dependant credit. It is wise to speak to a professional about how your tax situation will change during and after a divorce.