M&A Deal Essentials: Why “No Leakage” Is More Than Just Deal Jargon: The Locked-Box Deal

A fixed purchase price is one of the most attractive features of a transaction.

From a client’s perspective, a locked-box structure creates clarity: the price is agreed, and there will be no post-closing adjustment debates. What is signed is what gets paid. On paper, that simplicity is compelling. In practice, however, a locked-box deal only works if the period between signing and closing is handled with discipline, and if the concept of “no leakage” is taken seriously by everyone involved.

Locked Box Structure: How Fixed Purchase Price Deals Work

At its core, a locked-box structure means that the economic value of the business is fixed at a specific point in time, often before signing. From that moment onwards, the seller effectively promises not to extract value from the business (whether through dividends, payments, or other benefits) unless explicitly agreed. This is what “no leakage” is about. But in real transactions, value does not only move in obvious ways. It moves through decisions.

No Leakage Risks: Common Value Transfers Before Closing

Clients often associate leakage with large, visible transactions. In practice, it tends to be much more nuanced.

Typical examples include:

• payments to shareholders or related parties
• transaction-related costs charged to the business
• changes in compensation or bonus structures
• the assumption of liabilities that are not on arm’s length terms
• internal settlements or adjustments made in preparation for closing

Individually, these may not seem significant. But in a locked-box deal, each of them is tested against a simple question: Was value extracted from the business that the buyer has already priced in? That is where the complexity begins.

Locked Box Period: Monitoring Value Between Signing and Closing

One of the less intuitive aspects of leakage is its timing. The relevant period does not start at closing, it starts earlier, often well before the SPA is signed. From that point onward, every movement of value can become relevant. This is why transactions typically require a formal confirmation shortly before closing that no leakage has occurred, or full disclosure (a.k.a. No-Leakage-Notification). From a practitioner’s perspective, this is not a formality. It is a safeguard.

It ensures that what was assumed when the price was agreed still holds true when the deal completes.

Purchase Price Protection: How Small Decisions Create Deal Issues

One of the recurring patterns we see is that leakage rarely becomes problematic because of intention. It becomes problematic because of interpretation.

For example:

• Is a specific payment part of the normal course of business, or does it benefit the seller?
• Is a cost genuinely operational, or related to the transaction itself?
• Does a pre-agreed item fall within the scope of what is permitted, or exceed it?

These questions often only surface late in the process, sometimes just days before closing. At that stage, timing pressure is high, and even relatively small amounts can turn into negotiation points.

Buyer and Seller Trust in Locked-Box Transactions

Clients often approach leakage as a technical or accounting topic. In reality, it quickly becomes something more commercial.

A locked-box structure is built on trust:

• the buyer relies on the seller to preserve the agreed economic position
• the seller relies on the buyer not to challenge legitimate business activity

When questions arise around leakage, they rarely stay purely technical. They can affect how the parties perceive each other, particularly if issues are discovered late or were not clearly communicated upfront. This is why transparency during the interim period is as important as the contractual framework itself.

No Leakage Compliance: What Sellers Must Monitor

What makes leakage challenging in practice is not the concept, it is the execution.

During the signing-to-closing period, sellers must:

• monitor relevant payments and transactions
• identify anything that could fall within the leakage definition
• assess whether it is permitted or requires disclosure
• ensure that any required confirmations can be given with confidence

At the same time, the business still operates day to day. This creates a practical burden that is often underestimated at the outset.

Leakage Prevention: Avoiding Last-Minute Purchase Disputes

Most leakage disputes do not arise because the rules are unclear. They arise because something small was not identified early.

From experience, the smoothest transactions are those where:

• potential leakage items are flagged as they arise
• grey areas are discussed before they become time-critical
• both sides stay aligned on how the locked-box is intended to work

By contrast, issues that surface at the last moment tend to be more difficult to resolve, not because they are legally complex, but because they appear under pressure.

Locked-Box Deals: Protecting Deal Value Until Closing

The appeal of a locked-box deal lies in its simplicity. But that simplicity depends on careful handling of what happens after signing. “No leakage” is not just a legal term. It is a practical discipline that protects the agreed value of the deal and prevents late-stage surprises.

For business owners, the key takeaway is this: A fixed price only stays fixed if the underlying assumptions are respected all the way to closing. And in that sense, the locked-box promise is only as strong as the way it is managed in real life