Is there documentation required for income splitting?

If you are under 65 during the entire tax year, you will only be able to split the payments you directly receive from a registered pension plan. If you are older then you can split your pension income.  

Tax on split income (TOSI) applies to certain types of income of a child born in 2005 or later, and amounts received by adult individuals from a related business. Where TOSI applies, the disability tax credit, dividend tax credit and foreign tax credit can be used to reduce the individual's tax payable for the year.

Here is a great TurboTax article to help you: How do I split my pension income with my spouse?

Thank you for choosing TurboTax.