Open-Account Build-Up: When a Company Unknowingly Becomes Its Customer’s Bank

01When is open account a trading tool?

Open account is a practical way of working based on trust between buyer and seller. Rather than asking for a separate payment document, collateral or advance payment for every order, purchases made during a period are tracked in a single customer account and settled on agreed terms. This speeds up the commercial relationship, reduces operational workload and gives the customer room to plan cash.

The basic condition for open account to work well is that the balance genuinely closes at regular intervals. When receivables built up during a period are collected at the end of it, open account works as a transit zone. The company’s capital stays with the customer for a short, predictable time and then returns to the cash cycle.

The problem starts when this transit zone turns into a permanent store. If the balance never returns to zero and each period simply adds to the last, open account is no longer a commercial convenience; it has become undefined credit extended to the customer.

That is why the way open account works should be clearly defined at the start of the customer relationship. When it is known from the outset how often the account will close, how partial payments will be treated and at what point unclosed balances will be dealt with separately, open account remains a predictable tool for both parties. Left undefined, open account gradually writes its own rules, and those rules usually work against the company.

02How does build-up form?

Open-account build-up usually isn’t the result of one big decision. Instead, it builds up as small allowances that each seem reasonable on their own pile on top of one another. Each can be explained individually; taken together, they create a permanent balance.

• Partial payments: the customer pays part of the invoice instead of the whole; the rest rolls over to the next period.
• Old invoices settled with new payments: incoming payments are allocated to the oldest invoice, but the total balance does not fall.
• Shipments that never pause: new shipments go out before the balance closes, and every payment gives rise to a new open balance.
• Undefined reconciliation differences: returns, price differences or disputed items sit unresolved in the account.
• Person-dependent exceptions: verbal allowances granted because of a long-standing relationship are never recorded.

What these mechanisms have in common is that each is done to protect the commercial relationship. That is exactly what makes build-up dangerous: the build-up comes not from bad intent but from the sum of well-meant decisions, and so it is rarely questioned.

How quickly build-up forms varies with the sector, the customer’s size and the length of the relationship. In long, trust-based relationships build-up accumulates more slowly but more deeply, because the balance goes unquestioned. In newer relationships it becomes visible sooner. In both cases the common remedy is to review the composition of the balance regularly and to make rolled-over amounts visible under a separate heading.

03Why doesn’t it show up in reports?

The most striking feature of build-up is that it often doesn’t appear as a problem in standard collection reports. The customer pays every month, collection amounts are regular and the relationship looks healthy. But when each payment comes with new shipments that create a new balance, the overall open-account level rises quietly over time.

Management that looks only at total receivables or monthly collections may explain this rise as sales growth. Yet receivables growing faster than sales signals a rising need for working capital. The difference becomes clear when you look at the composition and age of the balance.

In the end, part of the company’s capital ends up financing the customer’s working capital. The company never made this as a conscious financing decision; it simply allowed the open account not to close.

Here the design of management reports plays a decisive role. Summary indicators such as total receivables, collection amounts and delay rates matter, but as long as they don’t show the age and movement of the balance, build-up stays hidden. Once indicators such as the age of each customer’s oldest open item, the date of the last full settlement and the change in balance between periods are added to reports, it quickly becomes clear how differently the picture can be read.

“In a well-designed system, a company does not unknowingly become its customers’ bank.”

04Indicators that make build-up visible

The way to make build-up visible is to read open account not as a single balance figure but with its time dimension. Several indicators should be tracked together:

• Gap between contractual terms and actual payment date: shows how many days late the customer really pays.
• Receivables ageing: shows how much of the balance has accumulated in which ageing buckets.
• Oldest unclosed balance: shows when the account last fully closed, or whether it ever did.
• Customer concentration: shows whether build-up is concentrated in a few customers or spread across the portfolio.
• Capital in use with the customer: measures how much company capital is actually tied up with a given customer.

When invoice due date, actual collection date and real financing period are read in a single chain, it becomes clear whether open account is a temporary trading tool or permanent financing. Without this chain, build-up is usually only noticed once a collection problem occurs.

The value of these indicators lies not in a single period but in how they change over time. A customer’s gap between contractual terms and actual payment steadily widening over several periods is a far more meaningful signal than a one-off delay. Likewise, a rising share of unclosed balances across the portfolio may indicate that collection policy needs to be reviewed.

05The impact on working capital

A credit sale makes part of the company’s capital available to the customer for a period of time. Seen this way, a receivable is the part of the company’s capital deployed with the customer. When build-up forms, that period becomes uncertain and the return of capital to the company becomes unpredictable.

If a company pays its suppliers on set terms while collecting from customers over a longer period, it has to cover the gap with its own resources or external financing. Build-up widens this gap permanently. As sales rise, so does the financing need; growth consumes cash instead of creating it.

So build-up is not just a collection issue. It is a working capital issue that directly affects the company’s financing costs, liquidity and ability to fund growth from its own resources. Real financial strength comes from a structure in which sales turn back into cash without consuming capital.

The cost of build-up is often lost within financing expenses. When a company increases its short-term borrowing, it usually attributes this to growth, stock needs or market conditions. Yet part of that need may stem from balances building up and never closing with customers. Once build-up is visible, the true source of the financing need is identified more accurately and management decisions are shaped accordingly.

06Managing build-up without giving up flexibility

The aim is not to remove commercial flexibility. For some customers, seasonal needs, sector payment habits or strategic relationships may call for different terms. What matters is that flexibility stays within defined limits and is managed through conscious decisions.

• Define, customer by customer, how long it should take for the open account to close.
• Track unclosed balances under a separate heading and assign owners to them.
• Record partial payments and offsetting practices.
• If there is a permanent financing need, handle it through a credit limit decision rather than open account.
• Make sure sales, finance and credit teams see the same indicators together.

These steps don’t weaken the customer relationship. On the contrary, they create a predictable working basis for both sides. The customer knows the room it has been given; the company can forecast its working capital needs and make financing decisions consciously.

You don’t need a sweeping transformation to start managing build-up. The first step is to identify which customers in the current receivables portfolio have balances that haven’t closed for a long time. This can usually be done with the company’s own data and quickly produces a concrete picture. The next steps are prioritising that picture, defining actions customer by customer and making the monitoring structure permanent.