Why would you ask only for responses from people outside the UK? Surely the people who will know most about tax and duty paid are those in the UK who had things shipped to them? You are assuming that anyone who shipped to the UK shipped to someone who bothered to tell them that they had to pay tax.
I have had stuff shipped to me and have paid tax to the courier when required, but I have not felt any need to tell the shipper about it.
VAT, duty and customs declarations for goods received by post or courier - paying, collecting your goods, getting a refund and documents.
www.gov.uk
There does seem to be a loophole that if you sell your own items to someone in the UK, not as a business, so you are not going to register for UKVAT, and the are under £135 value….
If the goods are marked as over £135 the odds are the recipient will pay VAT. Although the rule says the VAT is charged on the shipping too, I have not experienced this on my orders.