Under Article 79 of the Implementing Regulation to the Union Customs Code (UCC-IA), beneficiary countries which have begun to register in the Registered Exporter System (REX system) are entitled to the following preferential proofs:
• for consignments whose value of originating products does not exceed EUR 6 000, exporters shall provide declarations of origin,
• for consignments whose value of originating products exceeds EUR 6 000, registered exporters shall provide declarations of origin. In addition, the competent authorities of these beneficiary countries may continue to issue certificates of origin Form A for a period of 12 months for consignments of more than EUR 6 000 at the request of non-registered exporters. An extension of this transitional period by a further 6 months is possible at the request of the beneficiary country.

For the proper application of the REX system and the associated recognition of originated declarations made in the European Union, the beneficiary countries must comply with the conditions set out in Articles 70 and 72 UCC-IA. Some beneficiary countries that intend to start registration on 01/01/2017 have not met the requirements for the proper application of the REX system. At the same time, the 12-month transitional period ended on 31.12.2017, without an extension being requested. This means that certificates of origin Form A issued in these countries since 01.01.2018 or declarations of origin issued in the European Union may not be accepted for preferential treatment. These countries are therefore currently excluded from the GSP.
For this purpose, the European Commission has published a table in a table, in particular which countries are affected in detail:

Specifically, these are currently the following countries that have started to register on 01.01.2017 but have not yet properly applied the REX system and whose transition period has already ended:
Central African Republic, Congo, Cook Islands, Djibouti, Equatorial Guinea, Kiribati, Liberia, Mali, Micronesia, Nauru, Sao Tome & Principe, Sierra Leone, Somalia, South Soudan, Timor Leste, Togo, Tuvalu and Yemen.

According to Article 102 UZK-IA (3) UCC-IA, the declarant must check, in the case of imports from beneficiary countries, before declaring the goods for release for free circulation, that the conditions for granting preferential treatment have been fulfilled. This also includes the examination of whether there is a permissible proof of preference. For the countries concerned, therefore, an application for preferential grant on the basis of preference certificates issued or issued in 2018 is not permitted