For anyone thats interested this is how to work out your import costs.
First you need to phone customs on 01702 366077 . From this number they can find out the amount of Customs duty and VAT that you will have to pay.
The amount of duty varies, depending on what the item is.
The customs duty is worked out on the TOTAL INVOICE PRICE - INCLUDING CARRIAGE AND DELIVERY.!
Then on top of this price you need to add VAT at 17.5%.
So,,,,,
Work out your total bill from USA supplier, including delivery costs and insurance.
Add 2.7% Customs duty ( may vary- phone to check)
Add 17.5% VAT
That will give you your total.