In most situations where you want to challenge the accuracy or
completeness of a tax credit claim you will be able to use S14, 15
or 16 examination powers or your S19 enquiry powers. However, you
will not be able to use these powers where the year has become
final and you will only be able to revise the decision if you can
make a discovery decision.
There are two situations where you might be able to make a
discovery decision:
For guidance on the meaning of “conclusive decision”
see
CCM13020.
Where you believe a conclusive decision is incorrect because
the person’s income tax liability has been revised
and there is another error which is attributable
to fraud or neglect see
CCM13170.