General information only, not financial or tax advice. An accountant can help you adapt a forecast to your business.
This guide is for the owner of a small business that is busy and, on paper, profitable, yet still has tense weeks when payroll or rent is due before clients have paid: a design studio waiting on 60-day invoices, a contractor buying materials upfront, a shop stocking up before the holidays. Profit and cash are different things. A business can show a healthy profit for the year and still be unable to pay a bill next Tuesday. A short, rolling cash flow forecast is the tool that shows those weeks coming.
Profit versus cash
Your profit and loss statement records income when you earn it and expenses when you incur them. Your bank balance records money when it actually moves. The gap between the two is timing.
- You invoice a client $8,000 in March. That is March income, but if they pay on 60-day terms, the cash arrives in May.
- You buy $5,000 of stock in October for December sales. The cash leaves in October; the profit appears in December.
- Quarterly tax payments, annual insurance premiums and loan repayments drain cash in lumps.
The US Small Business Administration’s guide to managing your finances highlights cash-basis accounting as showing cash flow clearly and notes the value of a cash flow projection for planning ahead. A forecast is that projection, done week by week.
Why 13 weeks
Thirteen weeks is one quarter. It is long enough to see the next payroll crunch, tax payment or seasonal dip, and short enough that your estimates are still reasonably accurate. Each week, you drop the week just finished and add a new week at the end, so you always see a quarter ahead.
The template
Set up a spreadsheet with weeks across the top and these rows down the side.
| Row | Week 1 | Week 2 | … | Week 13 |
|---|---|---|---|---|
| Opening cash balance | ||||
| Customer receipts | ||||
| Other cash in (loans, owner investment, refunds) | ||||
| Total cash in | ||||
| Payroll and contractor payments | ||||
| Rent and utilities | ||||
| Supplier and stock payments | ||||
| Loan repayments | ||||
| Tax payments | ||||
| Software, insurance and other overheads | ||||
| Owner drawings | ||||
| Total cash out | ||||
| Net cash flow | ||||
| Closing cash balance | ||||
| Minimum cash buffer |
Each week’s closing balance becomes the next week’s opening balance. Add a row for the minimum buffer you want to keep, and use conditional formatting to turn any week red where the closing balance falls below it.
Filling in the cash coming in
This is the hardest part to estimate honestly, so base it on evidence.
Start with invoices already sent
List every unpaid invoice with its amount and due date. Then adjust for reality: if a client always pays two weeks late, put the receipt two weeks after the due date.
Add expected new sales
For work you expect to invoice in the next quarter, estimate the amount and when payment will actually arrive, not when you will send the invoice. Be conservative. A forecast that assumes every proposal is accepted is a wish list.
Include card and platform payouts
If you sell through card terminals, marketplaces or payment platforms, use the payout schedule, not the sale date.
Filling in the cash going out
Outgoings are more predictable, which is good news.
Fixed costs first
Rent, salaries, loan repayments, subscriptions and insurance usually have known amounts and dates. Enter them in the correct weeks.
Variable costs next
Stock, materials, contractor fees and shipping rise and fall with sales. Tie them to your sales estimates.
Do not forget the lumps
Annual renewals, equipment purchases and tax payments are easy to miss because they happen rarely. For US owners of pass-through businesses, the IRS explains that individuals, including sole proprietors, partners and S corporation shareholders, generally have to make estimated tax payments if they expect to owe tax of $1,000 or more when they file. Those quarterly payments belong in the forecast.
Pay yourself
Include owner drawings or salary. A forecast that looks fine only because the owner takes nothing is hiding a problem.
Profit is an opinion about the year. Cash is a fact about next Tuesday.
Reading the forecast
Once the rows are filled in, look for three things.
The lowest point
Find the week with the lowest closing balance. That is your pinch point. Is it above your minimum buffer?
The cause
Trace the pinch to its cause: a large tax payment, a slow client, a stock purchase. Knowing the cause tells you which lever to pull.
The trend
Is the closing balance broadly rising or falling across the 13 weeks? A falling trend in a busy period is a warning about pricing, payment terms or costs.
A short worked example
Imagine a three-person design studio with $18,000 in the bank. Payroll of $9,000 goes out every second Friday, rent of $2,500 on the first of the month, and an estimated tax payment of $6,000 falls in week 7. Two large invoices totalling $14,000 are due in week 5, but the client has a history of paying three weeks late.
Entered at their due date, the invoices make every week look comfortable. Entered at the realistic payment date, week 8, the forecast shows the balance dipping to around $1,500 in week 7, just as the tax payment leaves. With six weeks’ notice, the owner can ask the client for part-payment, move a software renewal, or arrange a small overdraft. Without the forecast, the studio would have found out on the day. The figures are illustrative, but the pattern is common.
What to do when a gap appears
The value of a forecast is the warning time. With several weeks’ notice, you have options.
Speed up cash in
- Invoice immediately when work is delivered, not at month end
- Chase overdue invoices with a polite phone call, not just an email
- Ask for deposits or stage payments on larger projects
- Offer an easy online payment link on every invoice
- Shorten payment terms for new clients
Slow down cash out
- Ask suppliers for longer terms or to split a large payment
- Delay discretionary purchases until after the pinch point
- Move annual subscriptions to monthly billing
- Time stock orders closer to when you will sell it
Arrange backup early
A line of credit is far easier to arrange before you need it. If the forecast shows a recurring seasonal gap, talk to your bank while the numbers still look healthy.
A weekly 20-minute routine
The forecast only works if it stays current. Set a fixed slot each week, such as Monday morning.
1. Enter last week’s actual bank balance as the new opening figure.
2. Compare last week’s forecast with what actually happened, and note big differences.
3. Update unpaid invoices and expected receipts.
4. Add the new week 13 at the end.
5. Check the lowest point and decide on any action.
Over time, comparing forecasts with actuals makes you a better forecaster. You learn which clients pay late and which costs you tend to underestimate.
Common mistakes
- Using invoice dates instead of payment dates for cash in
- Forgetting annual and quarterly costs such as insurance and estimated tax
- Leaving out owner pay
- Being optimistic about new sales
- Building it once and never updating it
- Ignoring sales tax or VAT collected, which is not your money to spend
Cash flow forecast checklist
- 13-week template set up with weeks across and rows down
- Opening balance taken from the real bank account
- Unpaid invoices entered at realistic payment dates
- New sales estimated conservatively
- Fixed, variable and lump-sum costs entered
- Estimated tax payments included
- Owner pay included
- Minimum cash buffer set and highlighted
- Lowest point identified and action planned
- Weekly update slot in the calendar
Takeaway
A business can be profitable and still run out of cash. A 13-week forecast, built from real payment dates and updated weekly, shows the tight weeks well in advance. Use that warning time to chase invoices, ask for deposits, adjust supplier terms and arrange credit before you need it.
