Understanding Purchase Orders with ISS Withholding

When you enter a purchase order for services, you must include the city code and service type code for each line on the purchase order. The system applies the city code to a voucher at the header level because all voucher lines must be for the same city. The system applies the service type code and whether ISS withholding applies at the detail level.

The system uses the values that you set up in the address book record for the supplier to obtain the default values for the service type code, and whether ISS withholding applies to the supplier. The system also uses the values that you set up in other applications for ISS withholding, including the associations between the service code and national service code, the GL offset account to use for the transactions, and the payee for the tax amount. The system reads the tables to which the set up information was written, and associates the information to the Purchase Order ISS Tax Information table (F76B705) when you save the purchase order.

After you enter the ISS information for purchase orders, you can modify the information if necessary. Because the system does not prevent you from making changes after ISS withholding has been calculated, you should use care in changing ISS information so that you maintain data integrity.

Note: The system uses ISS withholding information differently when you process a voucher that is associated with a purchase order than when you process a voucher for which no purchase order exists.