Cash Flow Forecast: 13-Week Template and Example

Quick answer: A cash flow forecast predicts how much cash will enter and leave your bank account over a set period, so you can spot shortfalls before they happen. The 13-week version breaks one quarter into weekly columns: opening cash, plus expected receipts, minus expected payments, equals closing cash. Update it every week and act on the lowest balance.

Most small businesses do not fail because they are unprofitable on paper; they get into trouble because cash arrives later than bills fall due. A weekly cash flow projection makes that timing visible. This guide gives you a 13-week cash flow template, a fully worked example, a method for forecasting receipts from your open invoices, and the levers to pull when the forecast shows a gap. For the wider picture, including tactics for improving cash flow in general, see our cash flow management guide.

This article is general information, not financial advice. Use your own figures and consider advice from an accountant for important funding decisions.

What is a cash flow forecast?

A cash flow forecast (also called a cash flow projection or cash budget) is a schedule of expected cash receipts and payments over future periods. It is different from a profit and loss statement in two ways:

• Timing. Revenue counts on the P&L when you invoice (under accrual accounting); cash counts in the forecast when the customer actually pays. Our guide to cash vs accrual accounting explains the difference.
• Non-P&L items. Loan repayments, owner drawings, asset purchases and tax payments affect cash but not profit in the same way. They all belong in a cash forecast.

Why use a 13-week cash flow forecast?

The 13-week cash flow forecast is standard in banking and turnaround work because it hits a useful balance: long enough to see a quarter's tax payments and seasonal dips, short enough that you can estimate each week with some confidence. It suits you if:

• Your cash balance swings a lot within a month (payroll weeks vs quiet weeks).
• You have large customers on long terms such as Net 60 or Net 90.
• You are considering a loan, line of credit or invoice financing and need to show a lender your plan.
• You have had a "how are we short this week?" moment.

A monthly 12-month forecast is still useful for planning hires and big purchases. Many businesses run both: 13 weeks for control, 12 months for strategy.

13-week cash flow template: the rows you need

Put weeks 1 to 13 across the top. Down the side, use these rows:

Section	Rows	Notes
Opening cash	Bank balance at start of week	Week 1 is your actual balance; later weeks equal the previous closing cash
Receipts	Customer payments on invoices; cash sales; other income (refunds, grants, loan drawdowns)	Forecast from your open invoices and expected new sales
Payments	Payroll; rent; suppliers; loan repayments; tax (sales tax/VAT, payroll tax, estimated income tax); subscriptions; owner drawings	Use actual due dates, not averages
Net cash flow	Total receipts minus total payments	Can be negative
Closing cash	Opening cash plus net cash flow	The number to watch
Minimum buffer	Your chosen safety level	Flag any week where closing cash falls below it

In a spreadsheet, the formulas are simple: net cash flow = total receipts − total payments; closing cash = opening cash + net cash flow; next week's opening cash = this week's closing cash. Our guides to building an invoice tracker spreadsheet uses the same formula style. The U.S. Small Business Administration's guide to managing your finances covers cash flow projections alongside the balance sheet and income statement.

How to forecast receipts from your invoices

Receipts are the hardest line to get right, and the one most forecasts get wrong by assuming customers pay on their terms. Build receipts from your open invoices instead:

1. List every open invoice with amount, due date and customer. Your accounts receivable aging report is the starting point.
2. Adjust each due date by the customer's real habit. If a client on Net 30 usually pays on day 44, put the cash in the week of day 44.
3. Discount doubtful invoices. Anything over 90 days overdue goes in as zero until you have a firm promise of payment.
4. Add invoices you will raise in the next 13 weeks, then apply the same payment delay.
5. Add cash sales and other receipts at their expected dates.

This is why consistent invoicing matters: every invoice needs a clear issue date, due date and unique number. You can create these quickly in the invoice generator and log them in your tracker.

Worked example: a 13-week cash flow forecast

A small design studio starts the quarter with $18,000 in the bank. Payroll and rent fall in alternate weeks, and a quarterly tax payment of $2,800 is due in week 6. All figures are illustrative.

Week	Opening cash	Receipts	Payments	Net cash flow	Closing cash
1	$18,000	$6,500	$4,200	+$2,300	$20,300
2	$20,300	$3,000	$9,800	−$6,800	$13,500
3	$13,500	$7,200	$4,100	+$3,100	$16,600
4	$16,600	$2,500	$9,600	−$7,100	$9,500
5	$9,500	$5,800	$4,300	+$1,500	$11,000
6	$11,000	$1,500	$12,400	−$10,900	$100
7	$100	$4,000	$4,000	$0	$100
8	$100	$9,500	$9,700	−$200	−$100
9	−$100	$6,000	$4,200	+$1,800	$1,700
10	$1,700	$8,800	$9,900	−$1,100	$600
11	$600	$7,500	$4,300	+$3,200	$3,800
12	$3,800	$6,200	$9,800	−$3,600	$200
13	$200	$9,000	$4,400	+$4,600	$4,800
Total		$77,500	$90,700	−$13,200

Check the totals: opening cash $18,000 + net cash flow −$13,200 = $4,800, which matches week 13's closing cash. The studio is profitable on its invoices, but cash falls to $100 in week 6 and goes overdrawn in week 8. Week 8's receipts include a $6,000 invoice that is already overdue.

Testing fixes in the forecast

The studio wants at least $5,000 in the bank at all times. It models two changes:

• Collect the overdue $6,000 in week 5 instead of week 8. Weeks 5, 6 and 7 rise by $6,000 to $17,000, $6,100 and $6,100. Week 8 receipts fall by $6,000, so week 8 still closes at −$100.
• Take a $4,000 deposit on a new project in week 7. Every week from 7 onward rises by $4,000: week 7 closes at $10,100, week 8 at $3,900, week 9 at $5,700, week 10 at $4,600, week 11 at $7,800, week 12 at $4,200 and week 13 at $8,800.

With both changes the lowest balance is $3,900 in week 8, positive throughout but still under the $5,000 buffer in weeks 8, 10 and 12. That tells the owner to either delay a planned equipment purchase, ask a big client for earlier payment, or arrange a small credit facility before week 8, not during it. Our comparison of invoice financing vs a line of credit covers the cost of each option.

What to do when your forecast shows a cash shortfall

A forecast is only useful if it changes what you do. Work through the levers in rough order of cost, cheapest first:

1. Bill everything that is finished. Unbilled work is the cheapest cash you have.
2. Collect overdue invoices. Call, not just email, the customers whose payments sit in your low week.
3. Ask for deposits on new projects, or stage payments on long ones.
4. Move discretionary payments. Equipment, marketing and non-urgent purchases can often wait a few weeks.
5. Talk to suppliers early. Asking for extended terms before a bill is due goes better than paying late without warning.
6. Arrange funding before you need it. Lenders are more willing when your forecast shows a temporary dip than when the account is already overdrawn.

Never solve a cash gap by holding back tax you have collected or payroll deductions. Those are owed to the authorities and penalties can be heavy.

Direct vs indirect cash flow forecasting

The method above is the direct method: you list actual receipts and payments. The indirect method starts from forecast profit and adjusts for non-cash items and changes in receivables, payables and inventory. Larger companies use the indirect method for long-range planning. For a 13-week forecast, the direct method is clearer and easier to check against your bank statement.

Common cash flow forecast mistakes

• Using invoice due dates as receipt dates. Use actual payment behavior.
• Forgetting irregular payments: quarterly tax, annual insurance, software renewals, bonuses.
• Leaving out sales tax or VAT. You collect it in receipts and pay it out later.
• Never comparing forecast to actual. The variance is how you improve the next forecast.
• Rolling forward without adding a week. Each week, drop the past week and add week 14 so you always look 13 weeks ahead.
• Ignoring owner drawings. If you pay yourself from the business account, it is a payment.

Weekly cash flow forecast routine

1. Enter last week's actual closing bank balance.
2. Update the receipts row from your open invoices and any payment promises.
3. Update payments with new bills and confirmed dates.
4. Roll the forecast forward one week.
5. Find the lowest closing balance in the next 13 weeks and decide what, if anything, to do about it.
6. Chase the invoices that drive that low point, using the tactics in how to get paid faster.

How invoicing habits change your forecast

Many cash gaps are invoicing gaps. Invoicing on completion rather than at month-end, taking deposits on large projects, offering an early payment discount and following up on day one of lateness all move receipts earlier in your forecast. Shorter terms move them earlier still. Each of these costs less than borrowing.

Next step

Open a spreadsheet, enter today's bank balance as week 1 opening cash, and list every open invoice with the week you realistically expect it to be paid. If a gap appears, start with the cheapest fix: send any work that is finished but not yet billed through the invoice generator today, with a clear due date.