Pigot’s Case and unauthorised alteration of a legal charge

April 16, 2026

Myranna Boult v Together Personal Finance Limited: Pigot’s Case and the voiding of an altered legal charge

Introduction

In Myranna Boult v Together Personal Finance Limited [2026] EWHC 809 (Ch), Mr Justice Michael Green considered the modern application of Pigot’s Case (1614) 11 Co Rep 26, the long-established rule that a material alteration to a deed, made after execution and without the knowledge or consent of the executing party, renders the instrument void. The appeal arose from possession proceedings brought by a lender seeking to enforce a legal charge over the borrower’s home. The central question was whether a manuscript alteration made after signature, adding a further parcel of land to the security, deprived the lender of its security altogether. The High Court held that it did.

It confirms that Pigot’s Case is not a historical curiosity. It remains a live and potentially decisive rule in modern secured lending and conveyancing practice. It also gives clear guidance on two matters that frequently generate argument, what counts as a deliberate alteration, and when materiality is to be assessed.

Factual background

In early 2018, Ms Boult sought to refinance existing borrowing secured against her home. The total indebtedness secured against the property was approximately £362,000. She used an independent mortgage broker to arrange replacement finance. The proposed facility from Together Personal Finance Limited was a 12-month bridging loan of £380,000 at 9 per cent interest, with fees of £8,595 added to the advance. The total sum repayable at the end of the term was £425,197.88. The intention was that the existing borrowing would be redeemed and the new loan repaid from the sale of the property within the year.

The security agreed by Ms Boult was limited to her house. Although she also owned a separate parcel of approximately 15 acres of agricultural land to the west side of the house, that land was not being offered as security for the new loan. The distinction mattered. When Ms Boult first attended her solicitors to sign the documents on 22 March 2018, she found that the field had been included in the legal charge. She refused to sign. She was told that the inclusion of the field was an error and that fresh documents would be produced.

The following day, 23 March 2018, Ms Boult returned and executed the replacement documentation, including a legal charge over the house only. The funds were then released and the previous secured borrowing was repaid.

The critical events occurred after execution. On 28 March 2018, after Ms Boult had signed the deed, the lender’s solicitors added in manuscript the title number of the field to the legal charge, apparently on the footing that both the house and the field formed the intended security. On 16 April 2018, the amended charge was registered against both titles at HM Land Registry.

Ms Boult did not know that this had been done. In September 2018 she received office copy entries showing that both the house and the field had been charged in favour of the lender. She queried the matter and treated it as potentially fraudulent. The police were involved, and the matter was referred to the Crown Prosecution Service, but no prosecution followed. In October 2018, once the lender became aware of the problem, the charge and restriction were removed from the field’s title.

The loan nonetheless remained unpaid. It had fallen due on 28 March 2019. The house was not sold, and in May 2023 the lender began possession proceedings in relation to the house. At trial in the County Court, His Honour Judge Porter-Bryant rejected Ms Boult’s reliance on Pigot’s Case, held that the alteration was an innocent mistake or administrative error and not material, and granted a possession order together with a money judgment for £738,783.89.

The issues before the court

The appeal was ultimately reduced to three central questions:

Whether the County Court judge was right to treat the post-execution amendment as an innocent mistake or administrative error, notwithstanding that it had been made deliberately.

Whether the amendment was material.

Whether, in those circumstances, Pigot’s Case applied so as to render the legal charge void.

The court’s reasoning

The legal framework

The appeal judgment approached the rule through Pigot’s Case itself, the discussion in Chitty on Contracts, and the Court of Appeal’s decision in Raiffeisen Zentralbank Osterreich AG v Crossseas Shipping Ltd [2000] 1 WLR 1135. The rule is rooted in non est factum. If a deed is materially altered after execution, without the executing party’s knowledge or consent, the altered instrument is treated as no longer being that party’s deed.

Michael Green J treated the modern formulation of the rule as containing two principal elements. First, the alteration must be deliberate rather than accidental. Secondly, it must be material, in the sense that it is potentially prejudicial to the legal rights or obligations of the party seeking to avoid the instrument. The respondent accepted that, because the alteration was admitted, the burden lay on it to show that the change had been made in circumstances insufficient to discharge Ms Boult from liability under the charge.

Deliberate alteration, not a disqualifying mistake

The County Court had held that the amendment fell outside Pigot’s Case because it had been made under a mistaken belief that the parties had agreed that the security should cover both the house and the field. The judge below therefore treated the alteration as both deliberate and mistaken.

The High Court rejected that analysis. Michael Green J considered that the authorities draw a real distinction between deliberate alterations and alterations made accidentally or by mistake. On the evidence, the operative act here was intentional. An unidentified solicitor deliberately inserted the field’s title number into an already signed legal charge in order to make the deed operate over the field as well as the house, and then caused the charge to be registered against both titles.

That there may have been internal confusion, or an incorrect assumption based on earlier lending arrangements, did not change the character of the act itself. The alteration was made on purpose and was directed at changing the legal effect of the deed. The court regarded it as an extraordinary course for a solicitor to amend a signed legal charge in that way without reverting to the chargor to confirm consent. The anti-fraud rationale of Pigot’s Case did not require proof of actual dishonesty. It was enough that the alteration was deliberate and of a kind capable of affecting rights under the instrument.

Materiality and potential prejudice

The High Court also held that the County Court had misapplied the test of materiality. The judge below had been influenced by the fact that the lender later removed the charge from the field and, when it eventually litigated, sought to enforce only against the house. He therefore concluded that there had been no actual or potential prejudice to Ms Boult.

Michael Green J held that this was the wrong approach. Following Raiffeisen, the question was whether the alteration was potentially prejudicial to Ms Boult’s legal rights or obligations under the instrument at the time the alteration was made. On that footing, the answer was straightforward. Once the field was added to the signed legal charge and the amended deed registered against its title, Ms Boult was exposed to the risk of enforcement against land which she had never agreed to charge. That was a clear instance of potential prejudice.

The fact that the lender later corrected the position did not undo that prejudice for the purpose of the rule. Nor did it matter that the lender ultimately enforced only against the house. The judgment makes an important temporal point: materiality is to be assessed when the alteration is made. If the alteration is deliberate and materially affects rights or obligations at that moment, the deed is void from then on. Later events do not revive it.

Application of Pigot’s Case

Once those conclusions were reached, the result followed. The respondent had not shown that the alteration was an accidental slip, nor had it shown that the addition of the field was immaterial. The post-execution insertion was both deliberate and material. Pigot’s Case therefore applied, and the legal charge was void. The lender could not enforce it by obtaining possession of the house.

The decision

The appeal was allowed. The possession order was set aside.

The money judgment, however, was not overturned. The High Court held that, properly analysed, the appeal was directed to the possession order and the validity of the security, not to the existence or amount of the underlying indebtedness. There had been no real challenge to the fact that the money had been advanced, that repayment was long overdue, or that substantial interest had accrued. In those circumstances, the court left the money judgment standing while removing the lender’s ability to enforce the void charge by possession.

Conclusion

This decision confirms that Pigot’s Case remains a rule of real practical force in modern litigation. It is not confined to antique deeds or technical disputes of historical interest. Where a signed security document is altered after execution so as to affect the scope of the charge, the court may still apply the rule with full rigour.

It also makes clear that an internal misunderstanding within a lender’s or solicitor’s office is not, without more, a safe answer. If the alteration itself is intentional and is made to change the instrument’s legal effect, the court may characterise it as deliberate even if the person making it believed, wrongly, that the amendment reflected the true agreement.

Equally significant is the court’s treatment of materiality. The focus is not on whether actual loss was later suffered, nor on whether the altered term was ultimately relied on. The relevant question is whether the unilateral alteration created potential prejudice when made. That approach is strict, but it reflects the policy of the rule. The law is concerned to prevent parties from taking the chance of altering an executed instrument in a way that may later be used to their advantage.

For lenders and conveyancers, the practical lesson is obvious. A signed deed is not to be treated as an administratively flexible document. If a substantive amendment is required after execution, proper consent and proper execution formalities must be obtained. A manuscript addition made after signature, followed by registration, carries obvious and serious risk. For professional indemnity insurers, the exposure is equally plain: what may appear to be a document-handling error can destroy valuable security and give rise to substantial downstream loss.

For defendants and their advisers, the case is a reminder that the registered position is not always conclusive of the enforceability of the underlying deed. Where there is reason to believe that a legal charge as registered does not match the document actually executed, the history of the instrument needs to be examined closely.

Finally, the judgment illustrates an important distinction between defective security and continuing indebtedness. On these facts, the lender lost the benefit of its proprietary security because the charge was void, but it did not lose the benefit of the debt itself. In practical terms, that distinction may be decisive in secured lending disputes.

Further Reading

Conveyancing Negligence Claims

Solicitor Negligence Claims

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