Cash flow forecast: common mistakes and how to fix them

2. Invoices issued late or poorly tracked

A reliable cash flow forecast depends on accurate invoicing.

In many companies:

• invoices are sent late
• data is incomplete
• some invoices are simply forgotten

This creates discrepancies between your forecast and actual cash flow.

Conversely, duplicated invoices or cancellations that are not updated can artificially inflate expected inflows.

These issues may seem minor, but they significantly reduce visibility. Your business may expect cash that will never actually be collected.

3. Lack of visibility on outstanding amounts and cash inflows

Your cash flow forecasting becomes approximate if your outstanding amount is not tracked accurately.

Many finance teams rely on incomplete Excel files that do not reflect real-time payment status.

If you do not know which invoices are paid, overdue or disputed, you cannot anticipate cash movements correctly.

Often overlooked, the aging balance provides an immediate and structured view. It allows you to classify invoices by age and identify truly at-risk amounts.

Without it, your cash forecast relies on overly generic assumptions and loses operational value.

4. Lack of automation

Without automation, your cash flow forecasting quickly becomes outdated and unreliable.

Companies that manually record payments and update forecasts are exposed to:

• missed updates
• timing discrepancies
• human error

As invoice volumes grow, while team size remains limited, these risks multiply.

Beyond time loss, the lack of automation prevents daily updates. Decisions are then based on outdated figures that no longer reflect reality.

5. Unanticipated disputes and unpaid invoices

Disputes and unpaid invoices heavily impact the reliability of your cash flow forecast.

A dispute can delay payment by several weeks. An unpaid invoice cancels expected cash inflows entirely.

Without tools to identify risky customers or track disputes, these events will continue to undermine your forecasts.

According to the Allianz Trade 2025 Customer Risk Barometer, 62,6% of companies experienced unpaid invoices, an increase of 11,6% compared with 2023, and 58,8% faced a customer default.

These risks are still too often underestimated in cash flow forecasting.

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The consequences of an inaccurate cash flow forecast

A cash flow forecast loses its value if it does not reflect actual inflows.

This leads to immediate and sometimes costly consequences for your business.

Bank overdrafts and fees

An inaccurate forecast can create unexpected liquidity shortages.

Your company may fall into overdraft even though your forecast showed a positive balance.

You may then need to rely on short-term financing, generating additional bank charges.

These bank charges, linked to overdrafts and debit interest, erode your margin and weaken your profitability. The more unpredictable your cash flow, the more frequent and difficult these charges become.

Financing difficulties

Poor forecasting also affects relationships with financial partners.

Banks rely on the quality of your projections to assess your ability to meet obligations.

Large discrepancies reduce your credibility and can lead to:

• restricted access to financing
• less favourable conditions (interest rates, guarantees)
• difficulty securing new funding

This can ultimately slow down your growth.

Stress for finance teams and time loss

Unstable cash flow increases pressure on finance teams.

Instead of focusing on optimisation and planning, finance leaders spend time managing urgent issues:

• renegotiating deadlines
• contacting banks
• constantly adjusting forecasts

This reactive approach creates stress and reduces efficiency.

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How to improve your cash flow forecast through accounts receivable

Your cash flow forecast becomes reliable only when your accounts receivable is properly managed.

When reminders are structured, financial data is up to date and communication is smooth, unpaid invoice risks are better anticipated.

Structure payment reminders and customer follow-up

The quality of your cash flow forecasting depends on how your reminders are organised.

Not all customers behave the same:

• some pay on time
• others regularly delay payments

A single approach for all customers is rarely effective.

The best approach is to create tailored reminder workflows based on:

• customer behaviour
• risk level

A high-risk customer requires strict follow-up, while a reliable customer can be managed more flexibly.

LeanPay, our accounts receivable software, simplifies this by automatically synchronising invoices, amounts, due dates and payments from your ERP or accounting software. → See all of our integrations.

Your teams start each day with a clear task list prioritising actions. This reduces missed follow-ups and improves forecast accuracy.

Automate reporting

Automation transforms your cash flow forecast into a true decision-making tool.

In our accounts receivable dashboard, key indicators such as DSO or aging balance are updated continuously.

LeanPay enhances your cash forecast by analysing payment behaviour over the last three months, rather than relying solely on due dates.

This realistic approach prevents misleading projections and aligns forecasts with actual cash flow.

Improve communication with customers

Cash collection reliability also depends on communication quality.

Every missing invoice, duplicate request or misunderstanding delays payment.

LeanPay provides a customer portal where they can:

• access their invoices
• pay online (card, transfer or direct debit)
• request payment plans
• report disputes

These features reduce friction and accelerate payments, making your inflows more predictable.

Anticipate unpaid invoice risks

A reliable cash flow forecast must include the probability of default.

This requires analysing each customer’s:

• financial strength
• payment history

LeanPay as a credit risk management software centralises data from providers such as Altares, Creditsafe, Ellisphere, Infolegale, Coface and Allianz Trade.

You gain access to:

• credit scoring
• payment history
• recommended credit limits
• insured amounts

Configurable alerts help detect critical outstanding amounts immediately.

This transforms your cash flow forecast into a proactive tool. Instead of reacting to delays, you can adjust payment terms or act earlier.

A cash flow forecast becomes reliable when customer tracking is structured and information flows seamlessly.

Your teams can rely on up-to-date data and better anticipate risks.

LeanPay makes the entire process clearer:

• structured reminders
• indicators based on real payment behaviour
• alerts for unpaid invoice risk

Let’s improve the reliability of your accounts receivable together 👇