Regulation 90C

Except as the Comptroller may otherwise allow, the claimant must make the claim by including the relevant amounts of refund in the appropriate box or boxes (as the case may be) on his return for the prescribed accounting period in which the claim is made.

If, at the time the claimant becomes entitled to make the claim, he is no longer required to make returns to the Comptroller, he must make a claim to the Comptroller in such form and manner as the Comptroller may determine.