IX.3.4. Responsibility of the Union's guarantor associations

Article 228 of the CAU

For the purposes of applying the TIR regime, the Union shall be considered a single territory. However, each Member State has at least one national guarantor association.

Article 164 of the AE
Article 11, paragraph 1, of the TIR Convention

A notification of non-discharge duly served by the customs authorities to its guaranteeing association under the TIR Convention shall have the same legal effects as if it had been served to another guaranteeing association by its own customs authorities.