Where an amount withdrawn from an RRSP when there is a cumulative excess amount in respect of RRSPs, when does the Part X.1 tax cease? CRA responded:
Since the income tax under subsection 204.1(2.1) is calculated monthly, at the end of the month … the time for calculating the cumulative excess amount in respect of RRSPs under subsection 204.2(1.1) and undeducted RRSP premiums under subsection 204.2(1.2) is at the end of each month. Consequently, when an individual has a cumulative excess amount in respect of registered retirement savings plans, the withdrawal of the excess reduces the amount of the undeducted RRSP premiums under subsection 204.2(1.2) and thereby the cumulative excess amount in respect of registered retirement savings plans for the months ending after the date of withdrawal.