Minimum order value surcharge

Dear SD experts,

I have one issue regarding the minimum order surcharge. As per our requirement if the sales order net value is less than $150 we charge minimum order value surcharge. The condition type is ZMIN. There are certain parameters to consider whether to charge or not the ZMIN in the sales order. These parameters are incorporated in the sales order user exit code.

My issue is the ZMIN is not charged in the sales order which is expected. However this is charged in the Invoice which is incorrect. The ZMIN condition type should behave similar to the sales order.In the VTFL configuration settings the Pricing type is "G".

Please provide your thoughts for the resolution. Appreciate your reply.

Thanks

M.Sridhar