Reply:Under the provisions of Clause 5, Article 29 of the Customs Law, Clause 8, Clause 10, Article 25 of Decree No. 08/2015 / ND-CP dated January 21, 2015 of the Government, the customs procedures for goods Export and import of single declarations are applied in the following cases:Goods subject to the provisions of Article 43 and Article 50 of the Customs Law:- Export goods of priority enterprises.- Goods in service of urgent requirements and special-use goods in service of security and defense.Goods in service of urgent requests are goods in service of overcoming consequences of natural disasters, epidemics or goods in service of urgent relief requests. Goods in service of urgent requirements must be certified by competent state agencies.Customs declarants regularly export and import certain goods, within a certain period of time of the same goods purchase and sale contract with the same buyer, seller, and through the same border gate are registered sheets. Customs declaration once within no more than 01 year.Within 30 days from the date of registration of an incomplete customs declaration or from the date of submission of documents to replace the customs declaration, the customs declarer must submit a complete customs declaration and related documents. customs records.One-time customs declarations are no longer valid to carry out customs procedures when there are changes in tax policies and export and import goods management policies.