In general, a Certificate of Origin (CO) is valid for one year from its date of issuance. For a back-to-back Preferential CO (PCO), depending on the Free Trade Agreement (FTA) concerned, the CO may share the same validity end-date as the original PCO issued in the first exporting country (e.g. a back-to-back Form AI will expire when the original Form AI issued in the first exporting country expires).�Please refer to the respective FTA's legal text available on the Enterprise Singapore website for more information on the validity of a PCO.