681. Time for assessment.

An assessment to income tax or capital gains tax may be made at any time not more than four years1 after the end of the year of assessment2 to which it relates3.

Where employment income, pension income or social security income is received in a year of assessment subsequent to that for which it is assessable, an assessment to income tax as respects that income may be made at any time not more than four years after the end of the year of assessment in which it was received4.