Guide · Plan

How to Build a Cash Flow Forecast

A profitable business can still run out of money. A cash flow forecast makes the timing visible, so you see the squeeze coming while you can still do something about it.

Plan
Cash forecast
13-week rolling • direct method
Opening balance420,000
Receipts+310,000
Payments(365,000)
Closing balance365,000

Profit and cash are not the same

Revenue you have recognised is not cash you have collected. A cost you have incurred is not a payment you have made. Debtors, creditors, stock, capital spending, loan repayments, tax, and dividends all move cash on a different schedule from the P&L. This is why a fast-growing, profitable business can be cash-negative: growth ties up money in unpaid invoices and stock long before it comes back.

Profit tells you whether the business works. Cash tells you whether it survives the month.

What a cash flow forecast is

A forward-looking projection of the money moving in and out of the business.

A cash flow forecast projects the money moving into and out of a business over a period, showing the opening cash, the net movement, and the closing cash for each interval. In plain terms, it projects your bank balance forward.

Most finance teams keep two horizons: a short-term operational forecast in weeks, for managing liquidity, and a longer-term forecast in months, linked to the budget, for planning.

13-week rolling forecast
Direct method
Week Receipts Payments Closing
W1180,000(210,000)390,000
W2120,000(305,000)205,000
W495,000(240,000)(35,000)
Closing balance is the early-warning line. The week-4 dip shows four weeks out.

The closing-balance row is the early-warning line.

Direct and indirect methods

Two ways to build one, answering different questions.

Direct

Build from expected receipts and payments, timed to when cash actually moves. Granular and timing-accurate, so it is the method for short-term operational forecasting.

Indirect

Start from forecast profit, add back non-cash items such as depreciation, then adjust for working capital and for financing and investing. The method for the longer-term view, and how the cash flow statement in a 3-way budget is built.

Use the direct method for the next quarter's liquidity, and the indirect method for the annual plan that has to tie to your P&L and balance sheet.

Plan

Building the forecast step by step

For a short-term, direct-method forecast.

1
Start with the opening cash balance
The actual figure in the bank today.
2
List expected receipts by week
Timed to when the cash is likely to land, not the invoice date.
3
List expected payments by week
Including payroll, suppliers, rent, tax, and loan repayments.
4
Net receipts against payments
For each week, to get the net movement.
5
Roll each week's closing balance
Into the opening balance of the next.

The closing balance line is the one that matters. It is where a dip four weeks out becomes visible.

The 13-week cash flow forecast

The standard short-term cash tool.

Weekly intervals, a quarter ahead, built with the direct method, and rolled forward every week so it always looks 13 weeks out. Thirteen weeks is far enough to give you room to act and near enough to stay accurate.

Key takeaway

The 13-week forecast is not about precision at week 13. It is about seeing the week-4 cash dip in time to do something about it, whether that is chasing a receipt, sequencing payments, or drawing on a facility.

Plan

Scenarios and cash runway

Cash runway

The number of months you can keep operating at your current net outflow. For a funded or pre-profit business, this is the number the board watches.

Runway
Cash on hand ÷ monthly net burn
Scenarios

Model a base case, a downside, and an upside. The single most common risk is receipts slipping, so stress-test collection timing, not just the amounts. A forecast where every customer pays on the day is not a forecast, it is a wish.

Plan

Common cash flow forecasting mistakes

×
Timing receipts to the invoice date rather than the expected payment date
×
Ignoring seasonality and lumpy outflows such as tax, bonuses, and capital spending
×
Running a single scenario with no downside
×
Building the forecast once and never rolling it forward
×
Never reconciling last period's forecast to actual, so the errors never get smaller
Plan

A faster way to forecast

By hand

Building and rolling a forecast by hand every week, chasing expected collection dates and re-keying the bank balance, is the repetitive part of the reporting cycle.

With Planir

Planir builds your cash flow forecast from your live accounting data, projects receipts and payments from your actual debtor and creditor positions, and links the longer-term view to your 3-way budget so cash flow, P&L, and balance sheet stay consistent. You review the assumptions, adjust the timing where you know better, and approve.

Common questions

What is a cash flow forecast?
+
A cash flow forecast is a forward-looking projection of the cash moving into and out of a business over a period, showing the opening balance, the net movement, and the closing balance for each interval.
What is the difference between the direct and indirect method?
+
The direct method builds from expected receipts and payments and suits short-term forecasting. The indirect method starts from forecast profit and adjusts for non-cash items and working capital, and suits the longer-term view that ties to the P&L and balance sheet.
What is a 13-week cash flow forecast?
+
A weekly, rolling, quarter-ahead forecast built with the direct method, used to manage short-term liquidity and spot cash dips early.
How far ahead should you forecast cash flow?
+
Most teams keep two horizons: a short-term rolling forecast, often 13 weeks at weekly intervals, for liquidity, and a longer-term forecast of 12 months or more at monthly intervals, linked to the budget.
What is cash runway?
+
The number of months a business can keep operating at its current net cash outflow, calculated as cash on hand divided by monthly net burn.

Explore other use cases

Planir is built for the planning and reporting cycles that funded, governed, and multi-entity businesses actually run.

Planning & forecasting

Budgeting and planning

Driver-based 3-way budgets and forecasts built from your live data, with every assumption documented and reviewable.

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Fundraising & M&A

Pre-transaction preparation

Investor-grade 3-way projections with documented assumptions, ready for fundraising, M&A, and due diligence.

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Investor obligations

Investor reporting

The financial section of every monthly and quarterly investor update, generated from your live data.

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See your cash flow forecast build itself

Connect your accounting data and Planir builds the cash flow forecast from your live debtor and creditor positions, ready for you to review.

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