Hello , The system automatically recalculates GST because the validation order in the configuration package is not respected (the Tax Engine prioritizes masters: customer/ship-to state, item, HSN/SAC before the GST Group Code). Quick solution: Import the dependent fields first (Document No., Location Code, Item No., etc.), and only afterwards the GST Group Code = "GST-0" (put it last in the processing order). Keep "Validate Field = Yes". Hope this helps you !