Article 157 Monitoring of the reference amount by the customs authorities(Article 89(6) of the Code)

The monitoring of the part of the reference amount that covers the amount of import or export duty, and of other charges due in connection with the import or export of goods, which will become payable with respect to goods placed under release for free circulation shall be ensured for each customs declaration at the time of placing of goods under the procedure. Where customs declarations for release for free circulation are lodged in accordance with an authorisation referred to in Articles 166(2) or 182 of the Code, the monitoring of the relevant part of the reference amount shall be ensured on the basis of the supplementary declarations or, where applicable, on the basis of the particulars entered in the records.

The monitoring of the part of the reference amount that covers the amount of import or export duty, and other charges due in connection with the import or export of goods, which may become payable with respect to goods placed under the Union transit procedure shall be ensured, by means of the electronic system referred to in Article 273(1) of this Regulation, for each customs declaration at the time of placing of goods under the procedure. That monitoring shall not apply to goods placed under the Union transit procedure using the simplification referred to in Article 233(4)(e) of the Code where the customs declaration is not processed by the electronic system referred to in Article 273(1) of this Regulation.

The monitoring of the part of the reference amount that covers the amount of import or export duty, and other charges due in connection with the import or export of goods where they are to be covered by the guarantee, which will be incurred or may be incurred in cases other than those referred to in paragraphs 1 and 2 shall be ensured by regular and appropriate audit.