If, on the occurrence of any of the events specified in sub-section (8) of section 50, there is enhancemnt or reduction in the amount of tax, penalty, interest or any other due under the Act, and such enhancement or reduction occurs after the commencement of recovery proceeding under sub-section (7) of section 50, the assessing authority, shall intimate the authority effecting such recovery, the actual amount to be recovered consequent upon such enhancement or reduction, within thirty days from the date of receipt of the order giving rise to the enhancement or reduction.