In the UK pretty much every courier offers a pickup service. You book it in, they give you a label to print, they turn up and take it. It's probably exactly like that. If you order from 6 shops, they ship 6 packages to you.
Great if you don't have access to a printer.
I recall (perhaps incorrectly) that Royal Mail once offered a service where you could buy an "online stamp", then you would write a long string of letters and numbers above the address on the envelope to send it. It was distinct from freepost.
"I collect 10 character long strings."