United Dominions Trust Ltd v Kirkwood [1966] 2 QB 431 was a decision of the Court of Appeal relating to what constitutes "banking business" as a matter of English law.

[2] United Dominions Trust was a finance company which brought an action to recover payment of a loan which it had made to a dealer.

The dealer defended the claim for repayment on the basis that the United Dominions Trust was not registered under the Moneylenders Act 1900 and hence the loan contract was unlawful.

United Dominions Trust claimed that it was exempt under section 6(d) of that Act because it conducted "banking business".

Diplock LJ stated: What I think is common to all modern definitions and essential to the carrying on of the business of banking is that the banker should accept from his customers loans of money on "deposit," that is to say, loans for an indefinite period upon running account, repayable as to the whole or any part thereof upon demand by the customer either without notice or upon an agreed period of notice.Both Lord Denning and Diplock LJ seemed to have been influenced by the consequence of not finding United Dominions Trust to be a banker within the meaning of the legislation, which would have meant that potentially thousands of agreements would have been rendered unenforceable.