VAT is 17.5%. OWC are first rate at markig the product value on the package so the right VAT is charged.
If you get Royal Mail delivery, they gold onto your package until you go to the sorting office and pay the VAT and another £10-£14, plus VAT on that.
If you get DHL delivery, they deliver immediately and bill you for the 17.5% VAT and an admin fee of something like £0.50, maybe as much as £1.50, which you can pay online with MasterCard, etc.
For me, DHL was a pleasure, Royal Mail / US Postal Service was slow and expensive.
I did receive a package about a month ago via Royal Mail, and they sent a letter with the charges, saying they are holding the package until payment is made, and I just followed an online link I believe to make payment, parcel was delivered following day. Don't know if this is a general standard practice, but not bad service I thought!!