It is important to measure your parcels accurately as described when you have made a booking. Couriers who will take your parcel will also measure the weight and dimensions so that it is within the size limit. Some couriers charge based on volumetric weight. Going over to a new kg can put you in a different price range and this will lead to the courier to put an additional cost to cover the space need to ship your parcel. The additional costs would need to be covered by you, often instances like these are not common but there are a few cases where there are discrepancies.