THESE are tough times for bean-counters. Recent revenue figures for two of the big four accountancy firms show small declines. Their auditing and tax-advice businesses are stagnant. But consulting is buoyant. PWC's consulting revenues, announced on October 4th, rose 7.9% between 2009 and 2010. Deloitte Touche Tohmatsu's grew by 14.9%. Ernst & Young's grew by a more modest 2%, but the trend is clear. For the big four—which also include KPMG—consulting now generates between a sixth and a third of global revenue, and this figure is growing.

Some people find this worrying. In America, accountants are barred from providing most non-audit services to firms they audit. (This rule was introduced after the collapse of Enron, whose auditor, Arthur Andersen, was thought to have gone easy on the crooked energy firm to protect its lucrative business advising it.) In other countries, however, the rules are less strict.

In Britain, firms may perform “internal audit” for a company—which involves giving some advice—while also performing its traditional external audit. KPMG, for example, last year won the race to provide both services to Rentokil, a British pest-control firm. Such an arrangement would be illegal in America.

Some academics argue that doing an internal audit makes an auditor more knowledgeable about a client, and therefore a better external auditor. The head of the Institute of Internal Auditors, a global industry body, disagrees: he says that it has the “potential to cause serious conflicts of interest”. KPMG insists it can keep the two functions suitably distant from each other. For PWC (formerly PricewaterhouseCoopers) in Britain, consulting is nearly as big (£804m) as audit (£893m). Some 16% of the firm's revenue comes from providing non-audit services to audit clients.

Britain's Audit Inspection Unit (AIU) says that the major firms “have policies and procedures in place to support audit quality”—but that improvements are needed. In a report in 2009, the AIU made several complaints: Deloitte's audit directors referred to their cross-selling work when discussing promotions; PWC stressed “business growth” when handing out bonuses for auditors; Ernst & Young's staff attached their sales figures to their submissions for annual review. In the AIU's annual report this year, it found that firms had generally taken its criticisms to heart. But it lamented “incomplete identification of the nature and extent of the threats to independence and objectivity”. The European Union, in a new “green paper” issued on October 13th, also fretted about auditor independence. Some countries favour continent-wide regulation of the industry.

Steve Harris, a board member of America's Public Company Accounting Oversight Board (PCAOB), gave warning in a recent speech that “it is critically important that the profession not regress” to compromising its independence. When asked if he has found any violations, the PCAOB's head of audit, Marty Bauman, says guardedly: “We have not publicly reported significant matters pertaining to independence recently.” By law, the PCAOB is barred from making disciplinary proceedings public until they have concluded.

An audit is supposed to be a cold-eyed outsider's look at a company's finances. For an auditor to provide its client even with tax advice or reviews of internal controls (which are both permitted under American law) involves a closeness that makes some observers nervous. If there really is synergy between providing these services and an audit, there is cause for concern about the auditor's independence. If, however, “Chinese walls” successfully separate audit and everything else, then the case for getting everything from one firm shrinks.