The SAAMCO scope-of-duty principle is the leading authority on how far a professional's liability extends when their advice is relied on by a third party. For RICS-regulated valuers and surveyors it is more than persuasive — the lead case, South Australia Asset Management Corp v York Montague Ltd [1996] UKHL 10, was itself a valuation case. The decision continues to shape how Apex Insurance Brokers Limited and its insurer markets price professional indemnity cover for residential and commercial valuers.
SAAMCO concerned a lender that had relied on a negligent property valuation. By the time the borrower defaulted the property market had fallen, and the lender recovered far less on enforcement than it had advanced. The lender sued the valuer for the whole shortfall. Lord Hoffmann held that a professional who provides information for use in a decision is liable only for the consequences of the information being wrong — not for the consequences of the decision itself. Wider market loss was outside the scope of the valuer's duty.
The principle was confirmed in Hughes-Holland v BPE Solicitors [2017] UKSC 21 and revisited in Manchester Building Society v Grant Thornton UK LLP [2021] UKSC 20. The Supreme Court now frames the test as: what risk did the professional assume responsibility for, and is the loss claimed within that risk?
A lender instructs a surveyor to value a property as security for a mortgage advance. The surveyor over-values it. The lender lends against the inflated figure. The borrower defaults, the lender repossesses, and the realisation falls short of the debt. The lender then sues the surveyor for the entire shortfall, which often includes losses driven by a falling market between the valuation date and the sale. SAAMCO disentangles two things: the loss caused by the valuation being wrong, and the loss caused by market movement. The valuer answers for the first, not the second.
The cap operates in two stages:
Worked example. A residential surveyor values a property at £500,000. A competent valuation would have produced £400,000 — an over-valuation of £100,000. The lender advances £350,000 against the £500,000 figure. The borrower defaults two years later, the market has fallen, and the lender recovers £280,000 on enforcement. The lender's loss on the loan is £70,000.
Applying SAAMCO, the ceiling is the £100,000 over-valuation. The actual loss is £70,000. The surveyor is liable for £70,000, the lower figure. Without the SAAMCO cap the surveyor could in theory have faced the entire £70,000 shortfall regardless of how much of it was driven by the market fall; SAAMCO makes explicit that any portion of the loss attributable to factors outside the valuer's scope of duty is excluded, and caps the rest at the over-valuation figure.
If the market had collapsed and the recovery had been £180,000, leaving a £170,000 shortfall, the cap would still hold the surveyor's exposure at £100,000, with the remaining £70,000 treated as market risk the lender chose to run.
RICS Valuation — Global Standards (the Red Book) sets the standard of care for the valuation itself. A breach is evidence of negligence, but the Red Book does not determine the scope of duty owed to the lender; that is a question of contract and tort law. A valuer can comply with the Red Book in form, miss the figure, and still benefit from the SAAMCO cap on the resulting claim. Equally, a surveyor who gives wider transactional advice — for example commenting on whether the lender should lend at all — may move from an information case to an advice case and lose the cap. Engagement letters and reporting templates matter.
Insurer reserves on valuation claims are set with the SAAMCO cap in mind. Quantum is rarely the entire lender shortfall; it is the over-valuation, then tested against the actual loss. That shapes claims experience and, over time, premium ratings for residential mortgage valuers, commercial valuers and the wider surveying book. Surveyors reviewing PI arrangements with Apex Insurance Brokers should expect underwriters to ask about instruction sources, lender panels, Red Book compliance, and whether reports stray into advice.
For sector context see Apex's pillar guides on surveyors' PI insurance, quantity surveyors' PI insurance and architects' PI insurance.
Apex Insurance Brokers Limited is authorised and regulated by the Financial Conduct Authority. Firm reference number 724952. This entry is general information, not advice on any particular policy.