Sorry, I also had a couple of questions regarding Simple Delivery please:

#1 - There is a return address printed on Royal Mail Simple Delivery labels, where are you getting this from? I would have thought it should be the ‘Primary returns address’ defined on this page in account settings but it definitely isn’t at the moment

https://settings3.ebay.co.uk/address/display?type=RETURN

#2 - This is the first week I’ve sold multiple Simple Delivery parcels and I had to print each label on a separate sheet. Is there a way of selecting and printing labels for up to 4 parcels on one sheet?

If you haven’t seen it Royal Mail’s Click and Drop also has the functionality shown below for single labels where you can choose where to print it. This is very useful to use up any remaining labels from sheets where you've only printed 1 or 2.