GST classification for paper envelopes and postcards applies a specified rate until the review date, excluding bundled stationery. Envelopes, letter cards, plain postcards and correspondence cards of paper or paperboard are classified in Schedule 3 and subject to GST at the prescribed rate until 21-09-2025; expressly excluded are boxes, pouches, wallets and writing compendiums of paper or paperboard containing an assortment of paper stationery including writing blocks.