we need to change to delivery method for a sold item, the label has already been generated, however the post office said the item needed a different courier provider as the item is too large for the current delivery provider.
How can I change the delivery method when delivery label is already generated?
You could 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.
The alternative would be to buy and pay for the correct postage yourself. You cannot add a new tracking number. All you can do is message the buyer with the new tracking details. You would still be able to add the new number to a "Not received" case if the buyer opened one though.
If the buyer paid for the unused label it will be automatically refunded to them in 30 days. If you paid for the original label (ie. have free postage on the listing) you can cancel it here: https://www.ebay.co.uk/claims/simple-delivery/refund/seller
