Separate operating cash from reserves
The operating account should hold enough for near-term payments plus a defined buffer. Excess cash can move to a reserve account so the business can see more clearly what is available for ordinary spending.
Treat tax money as committed cash
Sales taxes, payroll taxes and estimated taxes may sit in the bank temporarily, but they are not true free cash. Separating tax funds can reduce the risk of spending money that already has a future obligation attached to it.
Size the emergency layer around business volatility
A stable professional-services firm and a seasonal retailer need different reserve levels. Consider fixed monthly obligations, customer concentration, payment delays, seasonality, inventory cycles and access to reliable credit.
Use liquidity tiers
One practical structure is immediate operating cash, a liquid reserve in savings or money market, and a longer-term layer in CDs or other appropriate low-risk vehicles. The exact mix depends on how quickly funds may be needed.
Do not ignore bank concentration
Businesses holding large reserves should understand deposit-insurance limits and operational concentration at one institution. A secondary banking relationship can provide additional resilience, though it also increases administration.
Create rules for adding to and using the reserve
Define when excess cash is swept to reserves, what events permit a withdrawal, who approves transfers and how quickly the reserve should be rebuilt. A written rule prevents the reserve from becoming an informal spending account.
Primary sources and reference material
Build banking decisions around operating risk and total cost.
Use the account structure, permissions and liquidity rules that fit how the business actually receives, holds and moves money. Verify changing bank terms before implementation.