The Kittel principle intervention: Kittel in more detail: What is meant by ‘knew or should have known’: Contrivance
As well as indicating whether a taxable person ‘must have known’, some of the contrivance features detailed in VATF60000 can also be used to show that the taxable person ‘should have known’, although not all of the features will be relevant. For example, we would not expect a taxable person to know about the uniformity of the mark ups applied by taxable persons further up/down the transaction chain. However, they would of course know about such things as inadequate insurance, contacts etc. in relation to their own transactions. Factors such as these may help to establish that their transactions were ‘too good to be true’ and that the only reasonable explanation was that they were connected with fraud.