Once an investigation has been completed by the investigating authority, the Anti-dumping and Subsidies Commission, duties or quotas may be applied to defend industries in Jamaica that have demonstrated that they are being injured or face the threat of injury from imports. An antidumping or countervailing investigation shall be completed within 180 days (or 225 days with extensions). Safeguard investigations shall be completed within 180 days (or 270 with extensions). However, provisional duties may be applied at the stage of a Preliminary Determination by the Commission which is an interim decision taken about 90 days into the investigation on whether there is evidence of dumping or subsidisation, injury and causation. This allows the domestic industry to benefit from defence even before the investigation is completed.

In instances of unfair trade practices, the countermeasures are antidumping and countervailing duties. These duties are additional duties charged on top of ordinary customs duties on the subject product. They are intended to remove or offset the unfair advantage given to the foreign producer of the dumped and/or subsidized product. The duties will cause an increase in the cost of importing the subject product and in many instances, the importer will pass on the higher cost in the form of a higher price to its customers.

As a consequence, the duties reduce the excessive pressure faced by the domestic producers. It levels the playing field for domestic industries that are facing injury as a result of unfairly traded imports. Duties may be in place for five years initially and extended upon review if it is found that the unfair trade practice and injury are still of concern. In the case of safeguard measures, duties or quotas may be used to relieve the pressure of excessive import volumes that result in serious injury. Domestic industries are allowed breathing space to reorganize their operations to be able to compete effectively when the measure is removed. Duties may be in place for four years initially.