All VAT registered companies must complete two boxes (8 and 9) on their VAT returns showing the total value of any goods supplied to other EU countries (dispatches) and the total value of any goods accquired from other EU countries (arrivals).

Larger VAT registered companies must supply further information each month on goods traded with other EU countries. This is done using a Supplementary Declaration (SD). This applies to companies with a value of trade in goods above a legally set threshold for dispatches and arrivals. The figures, which may differ for dispatches and arrivals, is changed annually, normally towards the end of the preceding year.

Trade statistics are compiled from the detailed information supplied by the larger companies and the totals of EU trade declared in boxes 8 and 9 on VAT returns for companies below the threshold.