While contractual estoppel and its effect on the duty to advise is frequently invoked in mis-selling cases, and the list of such cases continues to grow, very few have reached trial (save for Alliance Group v RBS Property(PAG v RBS)) and so it is necessary to revisit the established common law principles.
An authoritative explanation of contractual estoppel was set out in Peekay Intermark Ltd v Australia and New Zealand Banking Group Ltd  EWCA Civ 386 where Moore-Bick LJ stated that
"Where parties express an agreement … in a contractual document neither can subsequently deny the existence of the facts and matters upon which they have agreed, at least so far as concerned those aspects of their relationship to which the agreement was directed. The contract itself gives rise to an estoppel".
This was endorsed by Aikens LJ in Springwell Navigation Corp v JP Morgan Chase Bank  EWCA Civ 1221 and has been followed in subsequent cases including Green v Royal Bank of Scotland  EWCA Civ 1197 and Crestsign Ltd v National Westminster Bank Plc  EWHC 3043 (Ch) (Crestsign), both of which have been discussed in previous issues, see here.
Crestsign remains a key authority on this subject as the judge found that the defendant had given advice of such a strong nature that it constituted a recommendation and that there was a duty of care between the parties. However, despite these findings, it was held that the terms of the loan documentation could successfully exclude any liability on the part of the defendant. In other words, the claimant was estopped from relying on the defendant’s advice as a consequence of the non-reliance terms in the agreement negotiated and entered into by the parties.
Crestsign also held that there could be a so-called ‘mezzanine’ duty of care. In particular, to the extent a bank does go further to give advice or information, it is under a duty ‘to give that explanation or tender that advice fully, accurately and properly’. The existence of the ‘mezzanine’ duty was considered in PAG v RBS and found to be a duty on the advisory spectrum that might arise depending on the specific facts.
The principles in Crestsign have been considered controversial by some commentators, but have been upheld in several recent cases including that of Finch v Lloyds TSB Bank Plc  EWHC 1236 (QB). This case is of note as the claimants argued not that advice had been given, but that the defendant was under a duty to voluntarily provide advice that might be contrary to its own interest, before the defendant and the claimant had even entered into a commercial relationship. The Court’s decision, in favour of the defendants, follows logically from the decision in Crestsign in that it would be truly exceptional for a duty to advise to arise in such circumstances, but it is interesting to consider whether if the bank had undertaken some limited duty of care, the mezzanine duty from Crestsign would have applied.
In summary, the status quo remains that a contractual estoppel may arise when provisions in the contractual documentation state that no advice was being given and this is sufficient to negate any duty to advise, however artificial it may appear. In addition, if, as in Crestsign, the non-reliance language is deemed to be a ‘basis clause’ – that is, a clause setting out the basis on which the parties were contracting rather than a limitation on liability – it would not be susceptible to challenge under s13(1) of UCTA.