If you have a court order or written agreement prior to May 1997, you can claim your child support payments on your income tax return. However, if you do not have a court order or written agreement prior to May 1997, your child support payments are not tax deductible. Please see the following link for more information, https://www.canada.ca/en/revenue-agency/services/tax/individuals/topics/about-your-tax-return/suppor...