Revenue growth is easy to track. Revenue concentration is often overlooked.

Client concentration risk arises when a single customer, or a small group, contributes a disproportionate share of total revenue. In many industries, large clients are expected. The risk emerges when dependency reaches a level where the business becomes exposed to decisions outside its control.

The 40% threshold is widely used as a practical benchmark.

When one or a few clients contribute 40% or more of revenue, lenders, investors, and acquirers begin to view the business differently. At this level, the loss of a single relationship can materially impact cash flow, disrupt operations, and place pressure on fixed costs.

This is not a regulatory limit, but it is a recognised signal of risk.

Financiers assess concentration when evaluating credit. A business heavily reliant on one client is inherently less predictable. As a result, lending terms may tighten, pricing may increase, or access to funding may be restricted.

The financial impact extends beyond revenue.

Cash flow becomes less stable. Forecasting becomes less reliable. A delayed payment or reduced order from a key client can create immediate pressure, particularly where overheads are fixed. Over time, dominant clients may also influence pricing and contract terms, gradually compressing margins.

There are strategic implications as well.

As dependency increases, decision-making can shift towards retaining a single client rather than building a balanced business. Product development, service delivery, and internal priorities may become aligned to one relationship, limiting broader market growth.

This becomes particularly relevant when considering valuation.

Buyers and investors favour diversified revenue streams. A concentrated client base introduces uncertainty, which is reflected in pricing. Deals may include earn-outs linked to client retention, or discounts applied to offset perceived risk.

Lenders take a similar view.

Higher concentration can result in stricter covenants, additional security requirements, or reduced appetite to fund. In some cases, financing is delayed until the revenue base is more balanced.

Managing this risk starts with visibility.

Understanding how revenue is distributed across your client base is essential. Tracking the contribution of key clients over time highlights whether concentration is increasing and where intervention may be required.

Reducing concentration requires a deliberate approach.

This may involve targeted client acquisition, expanding into new segments, or adjusting pricing strategies to rebalance the portfolio. The objective is not to replace strong clients, but to ensure the business is not dependent on any single relationship for stability.

A business can appear strong on the surface while carrying underlying exposure.

The 40% threshold is where that exposure becomes material.