The National Audit Office has done what the Palace has spent decades hoping no one would do with sufficient rigour: put the royal property portfolio under a forensic lamp. What the spending watchdog found is a system that, when described plainly, is difficult to distinguish from a private property racket underwritten by the public — and Andrew, Duke of York, sits at its most uncomfortable centre.

According to the NAO's published report, Andrew has been subletting cottages on the Royal Lodge estate in Windsor Great Park while himself paying what the report characterises as a peppercorn rent for the main residence. The arrangement means he was generating private rental income from Crown land on which he holds an exceptionally favourable long lease — a lease negotiated in 2003 at terms that have looked increasingly awkward as his public standing has collapsed entirely. He carries out no official royal duties, holds no working role, and makes no contribution that would justify the arrangement as a cost of public business. He is, in blunt terms, a private citizen profiting from a sweetheart deal on publicly maintained grounds.

The broader picture the NAO report paints is one of a property estate — worth billions and maintained substantially through the Sovereign Grant and public heritage budgets — functioning as a benefit-in-kind generator for an extended royal family. Princess Beatrice occupies an apartment in St James's Palace. Princess Eugenie holds a property at Kensington Palace. Neither pays market rent, or indeed any rent at all in a conventional sense. The cost is instead charged to the Privy Purse — the monarch's personal funds, technically — but both palaces are maintained through public money, meaning the public bears the cost of the fabric, the upkeep, and the infrastructure in which these arrangements sit.

A Buckingham Palace spokesman described the audit as consistent with the Royal Household's commitment to transparency. That line deserves to be read carefully. The report exists because the NAO has statutory authority to examine public expenditure — it was not volunteered. Calling it evidence of transparency is a bit like a company praising regulators for auditing them. The information is now public not because the Palace chose disclosure, but because an independent public body compelled it.

The NAO's mandate covers how public money is spent and whether it delivers value. Its report on royal residences is, in that context, a significant document. The Sovereign Grant — the public funding mechanism that replaced the Civil List — is calculated as a percentage of Crown Estate profits and has grown substantially in recent years, in part to fund the restoration of Buckingham Palace. The auditors are, in effect, asking whether the ancillary property arrangements represent comparable value. The subletting income Andrew extracted from Royal Lodge suggests the answer, at minimum in his case, is no.

What makes the arrangement structurally corrosive is not simply the money — the figures involved are not, by royal estate standards, enormous. It is the precedent and the optics. Andrew's public position evaporated after his catastrophic television interview regarding his relationship with convicted sex trafficker Jeffrey Epstein, his subsequent withdrawal from public duties, and the civil settlement with Virginia Giuffre. He is not a working royal. He is not a public servant. The lease and its attached benefits flow not from any legitimate public function but from the accident of birth and the inertia of an institution slow to revise its arrangements once made.

For Beatrice and Eugenie, the picture is less explosive but still structurally revealing. Both are private individuals with careers outside the formal royal structure. Both occupy prime central London real estate — at St James's Palace and Kensington Palace respectively — at no personal rental cost, with that cost absorbed by the Privy Purse. The NAO's report makes those arrangements a matter of public record in a way they have not been before. The document does not allege wrongdoing. It does not need to. The numbers do the work on their own.

The Palace's transparency defence will be tested not by this audit but by what comes next. The NAO report raises questions the institution has not answered: whether Andrew's lease will be renegotiated to reflect market rates, whether the subletting income will be addressed, and whether the property perks for non-working royals will be wound back as part of any future slimmed-monarchy settlement. King Charles has spoken publicly about a smaller, more focussed monarchy. The NAO's published findings now give that aspiration a concrete, documented baseline against which any future action — or inaction — will be measured.