The agreement requires members to impose tariffs on imports from all sources that are found to be dumped and prejudiced, with the exception of sources who have accepted a price commitment. In addition, the fee collected cannot exceed the margin of dumping, even if it may be lower. The agreement establishes two mechanisms to ensure that excessive tariffs are not collected. The choice of mechanism depends on the nature of the fee collection procedure. Where a member authorizes the importation and levies an estimated anti-dumping duty and only later calculates the specific anti-dumping duty to be paid, the agreement requires that the final fixing of the amount be made as soon as possible upon request for a final assessment. In both cases, the agreement stipulates that the final decision of the authorities must normally be taken within 12 months of a claim or a final assessment and that any refund should be made within 90 days. The agreement contains rules for calculating dumping margins. In the normal case, the agreement requires either a comparison of the average normal immigrant value with the average of all comparable export prices, or a comparison of transactions between normal and export prices (Article 2.4.2). Another basis for comparison can be used for targeted dumping, i.e. where there is an export price model that varies considerably from one customer, region or period to period. If, in this case, the investigating authorities explain why such differences cannot be taken into account in comparisons between average comparisons and transactions, the applicable average normal value can be compared to the export prices of individual transactions.
6.10 As a general rule, the authorities determine an individual dumping margin for each known exporter or producer of the product under investigation. In cases where the number of exporters, producers, importers or types of products involved is such that it is not feasible, the authorities may limit their verification to an appropriate number of interested parties or products using samples that are statistically valid on the basis of the information the authorities need at the time of selection. , or the largest percentage of the volume of exports from the country concerned, which can reasonably be assessed. An anti-dumping measure applies only in the circumstances of Article VI of the GATT of 1994 and as a result of investigations opened (1) and conducted in accordance with the provisions of this agreement.