I got an order from Ireland - never had this before - amazon did Royal Mail shipping as £5 but upon investigation the custom charges etc I don’t know what to do?
Shipping at the bottom is saying £18 and the order isn’t for that amount.
If you can’t make a shipment outside the UK, you should turn off the international shipping in the shipping settings from your Amazon Seller Center Account to prevent make this in the future.
Marketplace tax facilitator basically means that Amazon collected import duties and taxes directly from the buyer on your behalf and you are not being charged. Your customer paid extra and while these charges are displayed - they weren’t taken from you. So no need to worry.