The Big Four firm told its auditor, Grant Thornton UK, it should pass on cost savings from the rollout of AI and threatened to find a new accountant if it did not agree to a significant fee reduction. The discussions last year came amid an industry-wide debate about the impact of new technology on audit firms’ business and traditional pricing models. Firms have invested heavily in AI to speed up the planning of audits and automate routine tasks, but it is not yet clear if this will generate savings that are passed on to clients.