Yes, you can absolutely claim rent-related credits for previous years. In Canada, you can generally request adjustments to your tax returns for any of the previous 10 calendar years.

If you have used TurboTax Online, you can use the ReFILE option by signing in to your account, and on the side of the NETFILE return, you will have a ReFILE button. 

If you're using TurboTax Desktop, when you open your 2024 software, you click on “Change a filed return," choose the return you want to modify, click on modify return (in the NETFILE section), and follow the steps to apply the changes and ReFILE. If the steps are done in this order, the ReFILE button will be there.

In all cases, regardless of the software version used, you can do so directly in your My Account CRA or by mail by completing the following forms:

CRA: T1-ADJ T1 Adjustment Request

https://www.canada.ca/en/revenue-agency/services/forms-publications/forms/t1-adj.html

I've filed my tax return. Can I still make changes?

Thank you for choosing TurboTax.