Building a 13-Week Cash-Flow Forecast for a Small Business

A 13-week cash-flow forecast schedules the receipts and payments expected over the next thirteen weeks. Start with reconciled cash availability, use realistic transaction dates, and carry each week’s closing balance into the next week. The model helps identify funding needs; its usefulness depends on the completeness of the records and the assumptions behind them.

This article is part of our guide to cash flow forecasting and financial planning.

1. Reconcile opening cash and define the accounts covered

List the entities and accounts in the forecast. Reconcile book cash with bank balances and current availability, including holds, uncleared deposits, outstanding checks and pending ACH payments. Identify restricted funds and management-designated reserves separately. A raw bank balance is not automatically available for new spending.

Count pending payments once. For example, if a $5,000 outstanding check already reduces your opening available cash, do not also schedule it as a new Week 1 outflow. Alternatively, start from a clearly defined bank balance and deduct the check when expected to clear. Document the method and use it consistently.

Transfers between two accounts included in the consolidated forecast do not create a net cash inflow or outflow. Track account-level transfers separately when needed to ensure the paying account has funds. A tax reserve already included in opening cash cannot also be added as extra cash.

2. Build dated receipt and payment schedules

Use open invoices, collection history, sales orders, customer deposits, supplier bills, payroll calendars, tax schedules, debt agreements and approved capital commitments. Review enough historical activity to identify recurring and seasonal payments; six to twelve months can be a useful starting point, but it is a planning choice rather than a prescribed rule.

Place customer collections in the week funds are expected to become available. Use the actual terms, payment behavior and current customer information. Mark disputed or uncertain receipts. Do not count one sale as a cash sale, a customer deposit and a full invoice collection without subtracting the amounts already received.

Schedule the cash amounts for payroll funding, rent, suppliers, insurance, debt service, taxes, equipment and owner distributions. For payroll, identify whether the provider withdrawal already includes employee withholding and employer taxes. The other-tax line must exclude amounts already included in payroll funding. A credit-card purchase and the later card payment also must not both appear as bank outflows for the same purchase.

Customer deposits can be cash receipts before they are earned revenue. Loan proceeds and owner contributions are financing receipts, while principal repayments and owner distributions are cash outflows without being ordinary operating expenses. These distinctions explain why cash movement differs from profit.

We break down Business Tax Reserve Forecast separately in “Building a Business Tax Reserve Into Your Cash-Flow Forecast.”

3. Use a consistent thirteen-week grid

The grid below is a blank planning layout, not an automatically calculating spreadsheet. Copy it into your spreadsheet, replace Wk1–Wk13 with date ranges and add formulas. On a narrow screen, scroll the table horizontally to reach every week. Keep supporting transaction schedules and a notes column or separate assumptions sheet.

Add only the individual receipt lines to Total Inflows and only the individual payment lines to Total Outflows; do not add subtotals again. For each week:

• Net cash flow = total inflows − total outflows.
• Ending cash = beginning cash + net cash flow.
• Next week’s beginning cash = this week’s ending cash.
• Cash above or below policy = ending cash − the chosen minimum cash amount.

The minimum is an input based on management policy and relevant commitments or lender requirements. It is not generated automatically by adding receipts and payments. Show restricted or earmarked funds consistently with the opening-cash definition so the comparison measures the intended liquidity.

For an external spreadsheet resource, SCORE’s 13 Week Cash Flow Analysis page provides a worksheet download and an explanation of its intended use. Its format may differ from the layout above.

See “A Weekly Cash Dashboard for Owner-Managed Businesses” for more on Weekly Cash Dashboard.

4. Trace the first shortfall to specific transactions

Consider this hypothetical two-week segment. Assume all earlier weeks remain above a chosen $20,000 cash minimum and the modeled payments are counted once.

In this scenario, a separate $40,000 customer receipt previously expected in Week 6 moves to Week 7. The remaining Week 6 receipts are $18,000. Update both weeks so the $40,000 appears once. Week 6 payments include payroll and an unrelated tax payment, with employment taxes not repeated.

The forecast identifies a $7,000 policy shortfall in Week 6, not a negative cash balance. Review the collection assumption, discretionary commitments and supportable financing options. An anticipated loan draw is useful only if the funds can be available before the need arises.

Also inspect critical days. A $15,000 Wednesday payment can fail even when a $20,000 Friday collection produces a positive week-end balance. Use a daily schedule for tight weeks and include bank processing times.

5. Save the forecast before updating actuals

Keep a dated snapshot of the previous forecast. Then enter actual receipts and payments in a separate comparison or completed-week column. Explain each material variance: a receipt was late, an amount changed, a payment was omitted or an assumption was wrong. Reconcile actual closing cash to the defined accounts before using it as the new starting point.

Revise future assumptions, remove the completed week from the forward-looking view and add a new week at the end. Retain the completed weeks and prior snapshots for comparison. SCORE’s cash-flow management materials describe regular updates and forecast-to-actual comparison as part of cash management.

6. Keep the base case and downside case distinct

Use the most supportable amounts and dates for the base case. Do not deliberately distort every inflow downward and every outflow upward while calling the result the expected outcome. Model uncertain collections explicitly and record the basis for the estimate.

Create a downside case with specified changes, such as a two-week delay in the largest receipt, lower seasonal collections or an urgent repair. Compare the first low-cash date and the size of the gap in each case. Assign responses to a person and deadline, and reflect only agreed actions in the updated base forecast.

If you need help maintaining the records or interpreting the forecast, contact CPA Firm South Florida to discuss the required deliverables and review frequency, or see how outsourced CFO help keeps a rolling forecast current. A forecast remains a management estimate, even when an advisor helps prepare it.

Frequently asked questions

Does this forecast replace the income statement?

No. An income statement measures financial performance under the accounting basis used. The cash forecast schedules expected receipts and payments. A profitable sale can be collected later, and a loan receipt creates cash without sales revenue.

Should undrawn credit be included in opening cash?

No. Show available borrowing capacity separately. Include a proposed draw only as a dated financing receipt in a supportable scenario, considering approval conditions, fees and repayments.

How should owner distributions appear?

Show them as separate cash outflows when expected to be paid. Review the entity’s governing documents, legal and lender restrictions, tax consequences and owner obligations before deciding whether to make or defer them. A positive forecast balance alone does not authorize a distribution.