Do we like them?

Do we like Deloitte?

World's largest professional services network: audit, consulting, tax and advisory. Run from New York and London.

Our score: 4 out of 10. Not yet. The firm is huge and capable, but regulators and governments have found weak audit scrutiny and unchecked AI errors in work people paid a lot for.

Deloitte is the biggest of the Big Four. Its own profiles say it has nearly 500,000 professionals and about $75 billion in revenue. Joe Ucuzoglu has been Global CEO since December 2022. He took over from Punit Renjen, who ran it for seven years.

The big recent embarrassment was in Australia. A A$440,000 report for the welfare department had a made-up quote from a federal court judgment and references to research papers that don't exist. The revised version disclosed that Azure OpenAI was used. Deloitte refunded over A$97,000 of the fee.

Then Canada. A health staffing plan for Newfoundland and Labrador, which cost about C$1.6m, was found to have citations that appeared not to exist. Deloitte Canada said AI wasn't used to write it but was selectively used for a few citations, and it stands by the recommendations. An accounting watchdog opened an investigation.

On the audit side, the UK's Financial Reporting Council fined Deloitte £6.05m in October 2026 over its Go-Ahead Group audits. It said Deloitte failed to challenge the wrongful retention of over £30m of public money. The fine was cut from £11m because Deloitte cooperated. A £1.45m fine over the Mitie audit came earlier.

So we land at a 4. Deloitte is skilled and does cooperate when caught. But a pattern of weak scrutiny, both as auditor and as an adviser using AI, is the wrong thing to see in a firm that sells trust.