Cumulative Net Investment Loss (CNIL) was introduced in the 1988 tax reform legislation to prevent individuals from simultaneously deducting investment losses while sheltering investment income through the use of the lifetime capital gain deduction.
CNIL is the amount by which the total of investment expenses after 1987 exceeds the total of investment income after 1987.
Individuals who have a CNIL will have the ability to use the lifetime capital gain deduction reduced.
For business owner/managers, CNIL can be reduced by having the business pay dividends or interest on shareholder loan accounts, rather than salaries.
