Parcel heavier than Simple Delivery small parcel

[theregoesatenner]

My parcel weighs 2.5kg so should be medium parcel and not 2kg small parcel as per my listing using Simple Delivery.  What is the best action to take?   Do I  just use the label anyway and Ebay bill me the difference and I believe a £1 admin fee?  (Am I billed the difference between small and medium parcel or do they charge extra?)   I can't remember if Ebay chose the postage option or if I did. 

Or is it best to request refund on the postage label and book direct on RM?

[**peaseblossom**]

Its best to cancel/refund with buyer's agreement and relist with correct postage.

[style_wise]

Did eBay choose Small Parcel when they imported Simple Delivery to your existing listings? If so, then Royal Mail should accept it with no extra charge.

However if it were me, and I made a mistake in the postal charge, I would pay for the service myself and adjust the tracking number manually. If your Buyer bought the SD label they will be automatically refunded. If you bought it, you can substitute tracking number and request a refund - do this within 14 days'. This way the Buyer need never know!

Otherwise you could apologise to them, explain your mistake, and cancel/relist with the correct Medium Parcel size for the Buyer to repurchase.

[theregoesatenner]

Cancelling and relisting seems a bit of a hassle and would involve the buyer too.  I think I'll buy postage from RM and request label refund.  

Thank you for your replies.