Barristers and banks generally cross paths when something costly has gone wrong, or might go wrong, in relation to a transaction or product. At one end of the scale, the third-party guarantor of a small business loan may dispute their liability by questioning the validity of the guarantee. At the other, a barrister's services may be needed by an international bank caught up in a multimillion-pound trial relating to a syndicated loan or in relation to a complex regulatory investigation regarding large scale misselling of payment protection insurance.