IGST apportionment for unknown taxable persons follows prior-year tax collection ratios among States and Union Territories. Apportionment of IGST collected where the taxable person is not known is to be reported in a prescribed statement showing the total IGST to be distributed, the CGST portion, and the balance amount to be distributed among States and Union Territories. The allocation of the SGST or UTGST portion is to be made on the basis of the ratio of tax collected in the preceding year, with state-wise or UT-wise figures entered for the relevant year and month.