Item Tax does not really work in ERPNext if you have more than 2 tax templates

[asieftejani]

maybe this guy’s situation is similar to yours

Item tax template and Purchase tax template and sales tax template Correct approach explain please

I am not sure I have understood your problem properly but can you try this: - create 3 Purchase templates - call them Full KSI 20%, KSI single 15% and KSI minimum 5% everytime you make a purchase invoice you use the correct template - dont use item template as you will not attach it to the 5,000 items you have Will that help?