Ceili

Thank you......Do you know if I claim on my 2023 taxes only part of what I contributed to my RRSP? contributed $15,000. Can I only list $12,000 on my taxes?

I have over contributed to my RRSP amount for the tax year 2023. I have $12,000 worth of unused RRSP room. I contributed $15,000 by mistake. I have not included any of this in my initial filing with CRA. Can I only claim $12,000 from the amount invested? Should I wait until 2024 and then claim the total? Looking for advice to avoid penalties