Your cards or envelopes should be:A minimum of 90mm x 140mmA maximum 305mm x 381mm x 20mm (depth)Maximum weight allowable is 50g per item worldwideIf you need to send heavier items, contact your Account Manager. Large items, weighing up to 2kg, can be accepted for the IBRS service for the following countries only:BelgiumCyprusCzech RepublicDenmarkFranceHungaryGermany (1kg and depth of 50mm only)LatviaLuxembourgNetherlandsNorwayPortugalSlovakiaSloveniaSpainSwedenSwitzerlandUnited KingdomItems with the following dimensions are also classed as large or bulky:EnvelopesMinimum surface of at least 90mm x 140mmMaximum length, width and depth combined of 900mm, with no one dimension exceeding 600mmPacketsMinimum of 100mm x 70mm x 25mm (depth)Maximum length, width and depth combined of 900mm, with no one dimension exceeding 600mmItems in roll formMinimum length plus twice the diameter of 170mm but the greatest dimension must be at least 100mmMaximum length plus twice the diameter of 1040mm but the greatest dimension may not exceed 900mm