Belle Mead, NJ USA
Usually if you call your credit card company, BEFORE you leave the UK, and preferably from your home phone, and inform them that you will be travelling abroad, they will allow the card to go through. I have used my US credit card without issue in the UK, Middle East, etc. I always call them and tell them which countries I will be using my card in, and which dates I will be there. I have used my card to rent cars, dining, etc. I have not ordered anything in the UK to be delivered to an UK address, but as long as the credit card company knows ahead of time, it should go through. If you are staying at a particular hotel, you could give them the exact address items would be shipped to, which will prevent any delay.