Explanation · Money
How much cash should a business keep available?
Use upcoming bills, expected customer payments and possible delays to work out how much cash the business needs to keep available.
A healthy bank balance can feel reassuring on Monday and look very different after Friday’s payroll. Rent is coming out, a supplier needs paying, and the customer who promised to settle an invoice has asked for another week.
The question is how much of that balance the business can depend on when the timing goes wrong. A reserve gives you room to respond before a delayed payment becomes a missed obligation.
There is no useful reserve number that fits every business. Two companies with the same monthly expenses can need very different amounts because of when customers pay, how much stock they carry, the debt they service and how much they depend on a few customers.
Start with the payments you need to protect
Begin with the payments you must make before dependable receipts are expected to arrive. Then test what happens if one or two plausible problems occur. The aim is to identify how much cash lets you meet those obligations while there is still time to act.
Consider a restaurant. Customers may pay as they eat, but that does not make the cash schedule effortless. Payroll, rent, supplier payments and tax obligations have their own dates. A quiet trading period or a refrigeration repair can put pressure on money already needed for something else. A project business can face a different problem: weeks of work and wages before a single large invoice is collected.
These are teaching examples, not accounts of particular businesses. They illustrate why a reserve should reflect the way money moves through your business.
Decide which obligations you intend to protect. That might include payroll, required taxes, essential suppliers and a minimum balance required by a loan agreement. Write down the reason for your minimum so that another person can understand what it is meant to cover.
The balance, the available cash and the reserve
These three amounts are easy to confuse:
Bank balance is the amount shown today. Some of it may already be needed for payroll, taxes, rent, customer refunds or checks that have not cleared.
Available cash is the part that can be used after those near-term commitments are recognized. When preparing a forecast, keep those commitments in the payment schedule; do not subtract the same obligation twice.
Operating reserve is cash deliberately kept available for a defined interruption or delay. It is not every dollar in the account, and it should not be counted again as money freely available for a new purchase.
A reserve calculation becomes useful when you can explain both the amount and the problem it is meant to absorb.
Put the dates beside the amounts
Use a 13-week cash forecast to place payments in the weeks they will leave the account. Put receipts in the weeks you realistically expect them to clear. An invoice’s due date and a customer’s likely payment date may differ.
Start with the ordinary plan. Then change one assumption: a large customer pays three weeks late, equipment needs repairing, an important order requires cash before delivery, or sales fall for a month. Use a second scenario if another problem could reasonably happen at the same time.
For each scenario, find the lowest weekly balance. Compare that with the minimum you want to protect. The difference, if there is a shortfall, is the additional funding gap in that scenario. It is not automatically a universal reserve target or a recommendation to borrow that amount.
When a $55,000 balance is not enough
Suppose a fictional business starts with $55,000. During the next four weeks it expects $40,000 from customers and must pay $78,000 for payroll, rent, debt, taxes and purchasing. Its largest expected receipt is $22,000, included in week two.
Here is the timing behind the totals. Each closing balance includes all the receipts and payments up to that week.
| Week | Expected receipts | Required payments | Closing cash, ordinary plan | Closing cash, $22,000 receipt delayed |
|---|---|---|---|---|
| 1 | $6,000 | $18,000 | $43,000 | $43,000 |
| 2 | $24,000 | $21,000 | $46,000 | $24,000 |
| 3 | $5,000 | $19,000 | $32,000 | $10,000 |
| 4 | $5,000 | $20,000 | $17,000 | −$5,000 |
Under the ordinary plan, the lowest balance is $17,000. If the $22,000 receipt arrives three weeks late—in week five—it falls outside this four-week view. With the other payments unchanged, cash reaches negative $5,000 in week four.
If the owner wants at least $10,000 available for payroll and urgent costs, the gap is $15,000: the $10,000 minimum minus the projected negative $5,000 balance. The same delayed receipt cannot also remain in week two’s cash total.
That gives the owner a specific problem to work on. They can investigate collecting sooner, delaying a discretionary purchase, arranging credit before it is needed, reducing exposure to one customer, or building the additional reserve over time. Each option changes the business in a different way; revise the forecast to see whether the proposed response actually covers the gap.
Why another business may need a different cushion
Seasonality matters twice: during the quiet period and when the business buys stock or prepares for the next busy period. A monthly average can hide both demands.
Customer concentration matters too. Many small, predictable subscription receipts may create less timing risk than three large project customers, although cancellations and collection problems still need attention. Look at how much of your plan depends on any one payment.
Inventory, deposits and annual payments can create cash needs that are easy to miss when expenses are discussed only as monthly totals. Review the actual purchasing and renewal calendar.
Access to credit can provide another source of liquidity, but an unused line is not the same as cash. Limits, borrowing costs and renewal conditions matter. Check the agreement before treating it as dependable funding.
Finally, owners may choose to protect different obligations or different amounts of breathing room. Make that choice explicit rather than assuming everyone has the same meaning for “enough cash.”
Make the next review specific
Update the forecast with real payment dates. Write down the lowest projected balance, the largest expected customer receipt, the largest required payment and one disruption you want to test. Agree on which obligations the reserve must protect.
If there is a gap, give the next action to a named person and set a date to check the result. A plan to call a customer is still a plan; change the receipt assumption only when there is a reason to do so.
Review the calculation when sales timing, payroll, debt, purchasing or customer concentration changes. The reserve is a decision to revisit as the business changes, with the forecast showing why the amount needs to stay the same or move.