Deemed appointment of transitional officers ensures continuity under GST, with governments empowered to issue transitional rules. Existing officers appointed under pre-GST Central or State tax laws shall be deemed to be GST officers or Competent Authorities under the Act until specific prescription or notification, and the Central or State Governments may issue orders or make rules to secure a smooth transition to GST and address matters not expressly covered, so long as those measures do not conflict with the purposes of the Act.