Case Studies
PNB–Nirav Modi: The Letter of Undertaking No One Watched
CA Nikhil Gupta·June 2026·2 min readCase Studies

A banking fraud case study on PNB, LoUs, SWIFT and internal controls.

Finin2min Banking Fraud Story

PNB–Nirav Modi: The Letter of Undertaking No One Watched

The biggest frauds do not always need complex products. Sometimes they need a boring process that nobody checks properly.

By Finin2min Desk • Last validated: 17 June 2026 • Category: Banking Fraud / Controls • 7 min read
LoUBeforeControl FailureAfter!Operational Risk

Finin2min visual: original in-article illustration with no external-image dependency.

A Letter of Undertaking sounds like paperwork. In the PNB fraud, paperwork became a billion-dollar operational-risk lesson.

LoUA bank-backed credit instrument.
SWIFTMessaging outside core controls can be risky.
ControlsReconciliation is not optional.

The story

In February 2018, Punjab National Bank disclosed a fraud involving Letters of Undertaking. RBI’s press release referred to media reports of a fraud involving USD 1.77 billion.

RBI described it as a case of operational risk arising from delinquent behaviour by one or more employees and failure of internal controls.

That sentence is the entire case study. The product was not the only problem. The process around the product failed.

Fraud emerges: PNB disclosed unauthorised LoU-related exposure.

RBI response: RBI described the issue as operational risk and internal-control failure.

Aftermath: Banks and regulators re-examined SWIFT/core-banking controls.

The finance/legal twist

Off-balance-sheet or contingent obligations can become very real when invoked. The control twist is that systems must talk to each other.

If SWIFT messages, core banking entries, authorisation logs and reconciliation reports are not integrated, fraud can travel through the gap.

Practical example

If a branch issues a guarantee-like instrument but it is not recorded in the central liability system, head office may not see the exposure. The branch looks normal while the bank accumulates hidden risk.

Why this matters now

As banks digitise, operational risk becomes more technology-linked. A process gap can scale faster than manual fraud ever could.

Lessons for founders, finance teams and investors

  • Integrate messaging systems with core accounting systems.
  • Review dormant, high-value and exception transactions daily.
  • Do not let relationship managers override credit discipline.
  • Internal audit should test end-to-end transaction flow, not only paperwork.

Finin2min Takeaway

The PNB fraud proves that controls are not bureaucracy. Controls are the difference between a bank and a blind trust exercise.

Reality check

Fraud cases involve allegations, investigations and court processes. The safe learning is control design, not sensational naming.

Finin2min prompt

Ask your finance team: Which high-value obligation can be created outside the main accounting system?

PNBNirav ModiLoUSWIFTBanking Fraud