Origin determination for accessories, spare parts and tools affects originating status and value added calculations under preferential rules. Accessories, spare parts or tools supplied with a good as its standard equipment are considered originating when the good originates and are disregarded in tariff classification change tests if they are not invoiced separately and their quantities and values are customary; however, when a value added requirement applies, their value must be included in calculating value added as originating or non originating materials.