If substantial past losses relate to now-disallowed deductions, switching to the new regime may forfeit their set-off. In such cases, one can still opt out of the new regime by filing Form 10-IEA on or before the due date of return.

​If substantial past losses relate to now-disallowed deductions, switching to the new regime may forfeit their set-off. In such cases, one can still opt out of the new regime by filing Form 10-IEA on or before the due date of return.