A letter of undertaking is a formal written promise from one party to another to do something specific, or to refrain from doing something, within an agreed timeframe or set of conditions. In banking and real estate transactions, a letter of undertaking is most commonly given by a solicitor or attorney to a bank, promising that a specific legal step, such as registering a mortgage or releasing funds only once a particular condition is satisfied, will be properly carried out.
Because a letter of undertaking is treated as a serious professional and legal commitment, particularly when given by a solicitor to a bank, failing to honor it can carry significant professional consequences for the person who gave it, well beyond ordinary breach of contract, including potential disciplinary action by a professional regulatory body.
Letter of undertaking in plain terms
A letter of undertaking functions as a formal, written "I promise to do this specific thing" from one professional to another, relied upon precisely because the person receiving it needs certainty that a particular step will actually happen before proceeding with their own part of a transaction. A bank releasing mortgage funds, for example, might rely on a solicitor's letter of undertaking promising that the mortgage will be properly registered against the property, rather than needing to wait and independently verify that registration itself before releasing any money.
Common uses of a letter of undertaking
- A solicitor undertaking to a bank to register a new mortgage promptly once funds are released for a property purchase.
- A solicitor undertaking to redeem and discharge an existing mortgage from the proceeds of a property sale before releasing remaining funds to the seller.
- A party to a legal dispute giving an undertaking to a court to do, or not do, something specific while litigation is ongoing.
Why banks rely on letters of undertaking
Letters of undertaking allow transactions to proceed more efficiently by letting one party rely on another professional's formal promise rather than requiring every step to be independently verified before money changes hands, which would otherwise slow down routine transactions considerably. Banks specifically rely on solicitors' undertakings because solicitors are themselves regulated professionals who face serious consequences, including loss of their professional license, for failing to honor an undertaking once given.
Consequences of breaching a letter of undertaking
Breaching a letter of undertaking is treated as a serious matter, particularly for a solicitor, potentially resulting in disciplinary proceedings by the relevant professional regulatory body, in addition to any ordinary civil liability for losses caused by the breach, reflecting the fact that the entire system of relying on undertakings in professional transactions depends on undertakings actually being honored once given.
A bank's own legal team will typically review the specific wording of an incoming letter of undertaking carefully before relying on it, since an undertaking that is vague or conditional offers considerably weaker protection than one making a clear, unconditional promise.
Disputes over an undertaking's exact scope sometimes arise when circumstances change unexpectedly between when the letter was given and when it needs to be acted upon, which is why well-drafted undertakings specify precisely what triggers the obligation rather than leaving room for differing interpretations later.
Banks sometimes request a letter of undertaking from a solicitor specifically instead of waiting for formal registration to complete, since registration can take weeks, while the underlying transaction, such as releasing mortgage funds, often needs to proceed on a much shorter timeline.
International transactions sometimes rely on a letter of undertaking from a bank itself rather than a solicitor, particularly in trade finance, where one bank undertakes to another to handle documents or payments according to agreed terms before goods or funds actually change hands.
A party relying on a letter of undertaking from an unfamiliar professional, rather than one with an established reputation, may reasonably ask for additional confirmation or seek assurance through that professional's own regulatory body before proceeding with the transaction.
Professional indemnity insurance carried by solicitors and similar professionals provides an additional layer of financial backing standing behind their personal undertakings, giving the party relying on the undertaking some further assurance that compensation would be available even in the rare case the professional personally could not pay.
A bank relying on an undertaking generally keeps a signed copy on file as part of its own transaction records.
A professional who repeatedly fails to honor undertakings risks losing the trust of the very banks and counterparties who rely on this type of promise.