HM Revenue & Customs (HMRC) uses your import value to compile the UK's trade statistics. You don't need to complete a separate form to declare a value for trade statistics - you simply declare the value in Box 46 of the Single Administrative Document (SAD or form C88).
Value for trade statistics when customs duty is chargeable
If ad valorem customs duty (see glossary) is chargeable as a percentage of the value on your imported goods, then the value you have to declare for statistical purposes will be the same as the value calculated for customs purposes. Read more about the main method of calculating import value.
Value for trade statistics when customs duty isn't chargeable
If ad valorem customs duty isn't chargeable on your goods, then the value to declare for trade statistics purposes will be based on the price paid or payable to the seller. However, a number of adjustments must be made.
The following items should be added to the price paid or payable when calculating the value for trade statistics:
any other costs, charges and expenses connected with the sale and delivery of the goods to the port or place of importation in the UK
selling commission (except where incurred in the UK)
The following items should be left out of the calculation:
transport costs within the UK
selling commission incurred in the UK
duties or taxes chargeable in the UK
If there's no price paid or payable, you'll need to use one of Methods 2 to 6 to calculate your valuation. See other methods of calculating import value.