What goes into a forecast
BDC describes a cash flow forecast as a simple spreadsheet that lists the money coming in over the next weeks or months and compares it with the money going out. Start with a reconciled opening bank balance. Add expected receipts on the dates customers are likely to pay, not the dates you invoice. Then enter payments on the dates they fall due: payroll, rent, supplier bills, loan payments, and tax remittances and instalments.
BDC’s templates offer a 13-week view for near-term needs and a 12-month view for longer planning. BDC frames the 13-week version as a way to plan short-term needs and the 12-month version as a longer-term picture. A short horizon with weekly detail is generally better for catching a near-term shortfall.
A four-week illustration
Assume an opening balance of $12,000. In week one, $3,000 comes in and $5,000 goes out, leaving $10,000. In week two, $2,000 comes in and a $9,000 payroll goes out, leaving $3,000. In week three, a $20,000 customer payment is expected and $4,000 of bills are due, leaving $19,000. The figures are illustrative only.
Now assume the customer pays a week late. Week three then closes at negative $1,000, because $4,000 of bills are due and nothing has arrived. The forecast shows the problem with time to act, such as asking the customer about timing, negotiating supplier dates or arranging a credit facility in advance.
Common mistakes
Forecasting from invoices rather than expected collection dates is the most frequent error. Others include forgetting irregular payments such as HST remittances, source deductions or annual insurance, counting a receipt that is already in the opening balance, and treating sales tax collected as spendable money.
Mark which lines are firm and which are estimates, and run a slower-collection case alongside the expected one. Compare the forecast with actual results each week or month and adjust your assumptions. A forecast that is never compared with reality drifts quickly.
What to discuss with your accountant
Ask which regular obligations belong in the forecast and when each falls due for your business, including payroll remittances, sales tax and corporate tax. Share your aged receivables list so collection assumptions are realistic, and mention planned equipment purchases, hiring or owner withdrawals.
If you are applying for financing, a lender may want to see forecast assumptions as well as past statements. Your accountant can help you present them clearly and consistently.
Sources & editorial notes
Sources checked October 24, 2026. The examples are illustrative and provide general information. Discuss how the guidance applies to your circumstances with your accountant.
Rules and guidance can change. Use the current official source and confirm the treatment for your facts. To flag an error, contact Sora.