Article 29 (5)

A Contracting Party may increase such customs duty or other charge above the level referred to in paragraph (4) only if:

(a) in case of a customs duty or other charge imposed on or in connection with importation, such action is not inconsistent with the applicable provisions of the WTO Agreement, other than those provisions of the WTO Agreement listed in Annex W; or

(b) it has, to the fullest extent practicable under its legislative procedures, notified the Secretariat of its proposal for such an increase, given other interested Contracting Parties reasonable opportunity for consultation with respect to its proposal, and accorded consideration to any representations from such Contracting Parties.