In short: A 13-week cash flow forecast shows, week by week, how much cash your company will have over the next quarter. For a Swiss SME it takes one afternoon to build and 30 minutes a week to update – and it is the single best early-warning system against liquidity surprises from VAT, social charges, the 13th salary or slow-paying customers.
Why 13 weeks?
Thirteen weeks is one quarter. It is short enough to forecast with real data – open invoices, payroll, known bills – and long enough to see a cash gap coming while you can still act: chase receivables, delay a purchase, talk to your bank or adjust hiring. Annual budgets and P&L forecasts do not show this, because profit and cash move at different times.
What you need before you start
- Today's balances of all bank accounts and any credit line
- Your open customer invoices with due dates (accounts receivable)
- Your open supplier invoices with due dates (accounts payable)
- Your payroll calendar, including social charges and the 13th salary
- Recurring costs: rent, leasing, software, insurance
- Your VAT, social insurance and tax payment dates
- Your sales pipeline for new business you expect to invoice and collect within the quarter
How to build it in seven steps
1. Start from the actual bank balance
Use the real balance across all accounts on Monday of week 1, not the figure in your accounting system. Note your credit line separately – it is a buffer, not income.
2. Plan customer receipts by when cash really arrives
Put each open invoice in the week you realistically expect payment, based on how that customer actually pays – not on your 30-day terms. Add expected new invoices from the pipeline, with a haircut for uncertainty.
3. Add payroll and social charges
Salaries are usually your largest and least flexible outflow. Include the employer share of social insurance and pension contributions in the weeks they are actually paid, and do not forget the 13th salary.
4. Add suppliers and recurring costs
Schedule open supplier invoices by due date and add rent, leasing, software subscriptions and other recurring payments. Annual payments such as insurance premiums are easy to forget and hit hard.
5. Add the Swiss lump-sum payments
VAT, social insurance settlements and tax instalments arrive as large, irregular payments. They are the most common cause of cash surprises in otherwise healthy Swiss SMEs.
6. Add financing and one-offs
Loan repayments and interest, planned investments, dividends and expected equity or loan inflows.
7. Calculate the closing balance and set a minimum
Opening balance plus receipts minus payments gives the closing balance of each week, which becomes the opening balance of the next. Define a minimum cash level – for example one month of payroll and fixed costs – and flag every week that falls below it.
Large payments that belong in your forecast
- VAT payments
- Social insurance contributions and settlements
- Pension fund contributions
- The 13th salary
- Tax instalments
- Annual insurance premiums
Ask your Treuhand for the exact payment dates and amounts for your company, then enter them in the right weeks.
Keep it alive: the weekly routine
- Every Monday, replace last week's forecast with actual figures
- Look at the gaps: which customer paid late, which cost was higher?
- Add a new week 13 at the end, so you always look a full quarter ahead
- Act on every week that drops below your minimum cash level
Common mistakes
- Using payment terms instead of real payment behaviour
- Treating collected VAT as available cash
- Forgetting annual and quarterly lump sums
- Building the forecast once and never updating it
- Mixing up profit and cash
Frequently asked questions
What is a 13-week cash flow forecast?
A week-by-week plan of cash receipts and payments for the next quarter, starting from today's bank balance. It shows whether and when your company could run short of cash.
Is a 13-week forecast the same as a budget?
No. A budget plans revenue, costs and profit for the year. A 13-week forecast plans cash – when money actually comes in and goes out. You need both.
Can I build it in Excel?
Yes. For most SMEs a well-structured spreadsheet is enough. What matters is the weekly discipline of updating it, not the tool.
Need help setting it up?
Forecasting is one of the three pillars of our work at Gade Growth CFO Solutions, alongside goal setting and planning. We build the 13-week forecast with you and keep it running as part of our fractional CFO packages.