上市方式 · 2026-02-19

HKEX Review of Mitigation Plans for an Applicant's Key Customer Dependency

The Hong Kong Stock Exchange (HKEX) has signalled a material tightening of its assessment framework for listing applicants whose revenue is concentrated among a small number of clients, a shift that directly impacts the viability of certain high-growth but narrowly-diversified businesses seeking a Main Board listing. This recalibration, evident in Listing Decisions and divisional guidance issued throughout 2024 and into early 2025, moves beyond a simple quantitative threshold of customer concentration and places a far greater evidentiary burden on the applicant to demonstrate the sustainability of its revenue streams. For sponsors and legal counsel, the implication is clear: a standard “key customer dependency” risk factor in the prospectus is no longer sufficient. The Exchange now expects a detailed, forward-looking mitigation plan that is both commercially credible and independently verifiable, with the onus on the applicant to prove that the loss of a single major client would not render the business unviable. This article dissects the mechanics of this enhanced review, drawing on specific Listing Rule requirements and recent precedent to provide a practical roadmap for applicants navigating this critical gatekeeping hurdle.

The Evolving Regulatory Framework for Customer Concentration

The Quantitative Threshold and the Shift to Qualitative Scrutiny

The starting point for any analysis remains HKEX Listing Rule 8.07, which requires an applicant’s business to be “sustainable” and capable of generating sufficient revenue and profits. While the Rules do not prescribe a specific percentage for “key customer dependency,” the Exchange has historically flagged concentration where a single customer accounts for over 30% of total revenue, or where the top three to five customers account for more than 50%. This quantitative trigger, however, is no longer the primary determinant of a successful listing application.

The 2024 Listing Decision (LD-2024-001) explicitly stated that the Exchange will now assess the quality of the dependency, not just its magnitude. The decision focused on whether the concentration is a structural feature of the industry (e.g., a component supplier to a single mobile phone manufacturer) or a transient commercial arrangement. For the former, the applicant must show a long-term contract with enforceable minimum purchase commitments. For the latter, the Exchange expects a demonstrable pipeline of alternative customers or a clear path to diversification within the forecast period of the listing document. The burden of proof has shifted from “we are aware of this risk” to “we have a verifiable plan to manage this risk.”

The SFC’s Code of Conduct for Corporate Finance Advisors (paragraph 17.6) mandates that a sponsor must exercise “due diligence” to ensure that all material information in the prospectus is accurate and complete. In the context of key customer dependency, this obligation now extends to the sponsor independently verifying the applicant’s mitigation plans. This is no longer a desk-based review of board minutes or management accounts.

Sponsors are now expected to conduct site visits to the key customer’s premises (where permissible), review the customer’s own financial health and creditworthiness, and obtain written confirmations from the customer regarding the duration and terms of the existing relationship. The HKEX’s divisional guidance on “Customer Concentration” (2024) specifically notes that a sponsor’s failure to independently verify a customer’s commitment to a long-term supply agreement will be treated as a failure of due diligence, potentially leading to a refusal of the application or, in extreme cases, a referral to the SFC for disciplinary action.

Constructing a Credible Mitigation Plan: The Three Pillars

Pillar One: Contractual Anchoring and Revenue Visibility

The most robust mitigation plan is one that converts a customer relationship into a legally binding, long-term agreement with defined revenue minimums. This is not merely a “letter of intent” or a “memorandum of understanding,” both of which the Exchange treats as non-binding and therefore of limited evidentiary value. The applicant must present a formal master supply agreement or framework contract that includes:

Minimum purchase obligations (expressed in units or value) for a period of at least three to five years.
Termination clauses that are not one-sided in favour of the customer. The Exchange will scrutinise any clause that allows the customer to terminate “for convenience” or without cause, as this effectively negates the security of the contract.
Pricing mechanisms that are transparent and not subject to unilateral renegotiation. A cost-plus or indexed pricing formula is preferred over a “negotiated in good faith” provision.

For applicants in the manufacturing or technology sectors, a “take-or-pay” clause—where the customer is obligated to pay for a minimum volume regardless of actual offtake—provides the strongest possible revenue visibility. The HKEX’s Listing Committee has, in private rulings, indicated that such clauses can reduce the required discount for customer concentration risk in the valuation analysis.

Pillar Two: Demonstrable Diversification and Customer Pipeline

Where a long-term contract is not commercially feasible—for example, in the retail or e-commerce sectors where customers are end-users rather than contract parties—the applicant must demonstrate a tangible pipeline of alternative revenue sources. This goes beyond a list of potential customers in the prospectus.

The Exchange expects to see:

Signed letters of intent or heads of terms with at least two to three alternative customers, covering a minimum of 20% of the applicant’s current revenue from the concentrated customer.
A clear timeline for onboarding these customers, with specific milestones (e.g., product samples delivered, pilot production runs completed, first commercial orders placed).
A cost analysis of the switching costs for the applicant and the potential customer. If the applicant’s product is highly customised to a single customer’s specifications, the cost of re-tooling for a new customer must be disclosed and factored into the financial projections.

A 2025 review of successful Main Board applications in the healthcare sector showed that applicants with a diversified customer base across three or more distributors (each representing less than 30% of revenue) faced significantly fewer follow-up questions from the Listing Division than those with a single dominant distributor. The data point is clear: diversification, even if partial, is a more effective mitigant than a single, large contract.

Pillar Three: Financial Resilience and Sensitivity Analysis

The final pillar of a credible mitigation plan is a detailed financial sensitivity analysis that models the impact of losing the key customer. This is not a generic “worst-case scenario” paragraph. The Exchange expects a quantified, scenario-based analysis that covers:

Revenue impact: A 100% loss of the key customer’s revenue, with a second scenario showing a 50% loss.
Cost structure: The fixed versus variable cost base of the applicant. If a significant portion of costs (e.g., factory rent, machinery depreciation) is fixed, the loss of revenue will have a disproportionate impact on net profit.
Cash runway: A detailed cash flow forecast showing how many months the applicant can operate without the key customer’s revenue, assuming no new customers are secured.
Mitigation levers: Specific, identifiable actions the company can take to reduce costs or raise capital in the event of a customer loss. This could include pre-approved bank overdraft facilities, a committed equity line, or a plan to sub-lease unused production capacity.

The Listing Division now routinely requests that this sensitivity analysis be included in the “Risk Factors” and “Business” sections of the prospectus, not merely in the “Financial Summary” as a note. The analysis must be signed off by the applicant’s auditor and reviewed by the sponsor’s financial advisory team.

Practical Implications for Applicants and Their Advisors

The Due Diligence Checklist for Sponsors and Counsel

For law firms advising on a listing application, the due diligence exercise has expanded materially. The standard checklist now includes:

Customer contract review: Full set of contracts with the top customers, with particular attention to renewal, termination, and change-of-control clauses.
Customer financial health: A review of the customer’s audited financial statements (where publicly available) or a credit report from a reputable agency (e.g., Dun & Bradstreet) to assess the customer’s own ability to continue purchasing.
Industry benchmarking: A comparison of the applicant’s customer concentration with that of its listed peers. If the industry norm is 20-30% concentration and the applicant is at 60%, the explanation must be compelling.
Management interviews: Detailed discussions with the sales and operations teams to understand the historical relationship with the key customer, the decision-making process at the customer’s end, and any potential competitive threats.

A failure to identify a material weakness in a customer’s financial health—such as a significant drop in the customer’s own revenue or a credit rating downgrade—will be treated as a due diligence failure. The SFC’s enforcement actions in 2023 against two sponsors for inadequate due diligence on customer concentration serve as a clear warning.

Timing the Application and Managing Exchange Queries

Applicants with high customer concentration should expect a longer review timeline. The Listing Division’s standard 20-working-day period for first-round comments is often extended to 30-40 working days for these cases, as the Exchange requests additional documentation to support the mitigation plan.

The most common follow-up queries from the Exchange include:

“Please provide the audited financial statements of Customer A for the past three years.”
“Please explain why the master supply agreement with Customer B does not include a minimum purchase obligation.”
“Please provide a detailed breakdown of the cost savings the company would implement if Customer C’s revenue were lost.”
“Please confirm whether any of the company’s directors or shareholders have a personal relationship with the decision-makers at Customer D.”

Sponsors should prepare a “query response book” containing all supporting documentation for the mitigation plan before the application is formally submitted. This proactive approach can reduce the number of iterative rounds and shorten the overall timeline.

The Consequences of an Inadequate Plan

The most severe consequence of an inadequate mitigation plan is a formal rejection of the listing application. The HKEX has the power to refuse an application under Listing Rule 9.10 if it is not satisfied that the applicant meets the suitability requirements. In 2024, the Exchange rejected three applications on the grounds of unsustainable customer concentration, all of which had failed to provide a credible mitigation plan.

Short of a rejection, the Exchange may require the applicant to restructure its business or its listing vehicle. This could involve:

Acquiring a competitor to diversify the customer base before listing.
Spinning off the concentrated business unit and listing only the diversified portion of the group.
Issuing a profit warning in the prospectus that explicitly states the risk of customer loss and its potential impact on future earnings.

In extreme cases, the Exchange may require the applicant to provide an independent expert’s report on the sustainability of its customer relationships, similar to the “profit forecast” reports required under Listing Rule 11.18. This is a costly and time-consuming exercise that should be avoided through proper upfront planning.

Actionable Takeaways for Decision-Makers

Sponsors must independently verify the financial health of a listing applicant’s key customers, not merely rely on the applicant’s representations, with a credit report and audited financial statements being the minimum standard of proof.
A binding, long-term contract with minimum purchase obligations and restricted termination clauses is the single most effective mitigation tool for high customer concentration, and its absence should be treated as a material red flag in the due diligence process.
Financial sensitivity analysis must be quantified and scenario-based, modelling a 100% and 50% loss of the key customer’s revenue, with a clear identification of the company’s cash runway and specific cost-cutting levers.
A demonstrable pipeline of alternative customers, supported by signed letters of intent or heads of terms covering at least 20% of the concentrated revenue, is a non-negotiable element of any credible mitigation plan.
The listing timeline for applicants with key customer dependency should be budgeted at 30-40 working days for first-round Exchange comments, with a comprehensive “query response book” prepared in advance to minimise iterative delays.