Parcel dimensions on pre-paid label incorrect

[sham-68]

I am trying to post an item but the pre-paid label is for an Evri medium parcel with a maximum size of 61 x 46 x 46cm but the item is actually 86 x 20 x 20cm. I cannot change the parcel size an option, is it the sum of overall dimensions that is important?  The weight is less than the 10kg on the label

[**peaseblossom**]

Simple Delivery approximates weight but I don't think they approximate size.   If you want to be sure it's best to cancel/refund the transaction with the buyer's agreement (via the dropdown menu arrow for the item on your orders list) and relist with correct postage for the buyer to buy and pay again. 

@sham-68