TAXATION MANAGEMENT USING ASYCUDA++ Ó UNCTAD - SITE (V1.15) A.18 Inserting Rates of Taxation To  add  rates  of  taxation  or  alter  existing  rates,  select  the  Commodity  Code  that  you  want  to change. The Commodity Code can be selected by either scrolling through the codes on screen, or by using the   'Options'  button  to  more  quickly  access  particular  Commodity  Codes.  Select  the 'Update' button to view the Commodity Code details. This is an example screen for Commodity Code 902710. Figure A.11: MODCHQ: Functions: Database Management: Customs Tariff: Commodity Code Insert Validity Dates "from .... to" in the format dd/mm/yyyy. Important: See the Section on ‘Validity Dates’. The bottom part of the Commodity Code screen appears as follows Figure A.12: MODCHQ: Functions: Database Management: Customs Tariff: Commodity Code You can alter existing rates or insert new rates directly in the tax column.  Each change or addition of rate adds a new Commodity Code taxation line to the table. Taxation lines added in this manner can only be deleted if the taxation line is not valid and has never been valid, i.e. the taxation line record has never become 'current' as regards the start validity date. See 'Validity Dates' below. Tip: for development purposes, ‘Validity Dates' for trial changes to taxation lines should be sufficiently in the future to not become current.