Customer Concentration: The Single Number That Frightens Buyers

The MeasureHow buyers measure concentration

The first calculation is the simplest one: the largest client as a percentage of revenue, then the top five together. A buyer will do it before the first meeting if the information is available and will ask for it if it is not. In practice anything above about a quarter of revenue in one account starts to change the shape of an offer, and above a third it changes the structure of the deal entirely.

The second calculation is less obvious and matters more. A buyer looks at contract expiry dates against that concentration, because a large account with two years to run and a large account up for retender in September are different risks wearing the same number. They will also look at whether the contract is with a site, a region or a national procurement function, since the last of those can be lost through a decision nobody in your business ever meets.

The third thing they check is who owns the relationship. A major account managed by the owner personally is priced as a risk that leaves with the owner. The same account with a named technician, a documented service history and a client contact who deals with the office is a considerably safer proposition, and the difference is entirely a matter of how the business has been organised.

The CapWhy one large contract can cap a valuation

Concentration does not reduce an offer proportionally. It caps it, because it changes what the buyer is willing to pay at completion rather than what they think the business is worth. A round where a third of the income depends on one procurement decision is a round where a buyer wants that decision to have gone their way before the money is handed over.

In practice that shows up as structure. More consideration deferred, an earn-out tied to the retention of the named account, a longer handover so the owner is still present at the next renewal, or warranties specific to that contract. Each of those is a mechanism for the buyer to pay for the account only if it survives, and each of them moves risk from them to you.

It is worth being clear that a buyer is not being unreasonable. They are pricing what they can see. The same logic runs in your favour where the book is spread: a business whose largest client is under a tenth of revenue is a business where no single conversation can damage the earnings, and buyers pay for that with a simpler deal rather than a bigger discount.

There is also a sector-specific version of the problem worth naming. Concentration in this trade often hides inside a sector rather than a client. Six contracts across one retail group, or a book weighted heavily towards a single type of food production site, behaves like one account when procurement changes hands. Count exposure by decision maker rather than by invoice.

Concentration does not reduce an offer proportionally. It caps what a buyer will pay at completion.

The Twelve MonthsWhat actually reduces it in a year

Winning new work in the postcodes you already serve is the only lever that improves concentration and route density at the same time, which makes it the obvious place to start. It is slow, because contracts in this trade mostly move at renewal, so a year of deliberate local selling changes the picture rather less than owners hope and rather more than doing nothing.

Staggering renewal dates is faster and almost free. Where several large contracts come up in the same quarter, agreeing a shorter or longer term with one or two of them spreads the exposure across the year and removes the cliff a buyer can see in the schedule. Most clients are indifferent to the change and it takes one conversation each.

The third lever is transferring the relationship. Introduce the named technician as the day-to-day contact, run the annual review with them present and then leading, and make sure the reporting goes to the office rather than to your mobile. Done twelve months ahead this converts a personal relationship into a business one, which is the specific thing a buyer is paying less for when it is absent.