What is working capital, and why does it matter so much?
Working capital is the money tied up in running the business day to day — current assets minus current liabilities. It matters because it is where cash goes to hide.
What is in it:
Stock (inventory) — cash converted into things sitting on a shelf.
Receivables (debtors) — work done, invoiced, and not yet paid for. Cash you have earned and do not have.
Payables (creditors) — money you owe suppliers. Effectively an interest-free loan from them, which is why it reduces your working capital requirement.
The cash conversion cycle. The number of days between paying for something and being paid for it:
Days inventory outstanding — how long stock sits.
Plus days sales outstanding — how long customers take to pay.
Minus days payable outstanding — how long you take to pay suppliers.
The result is how many days of operating costs you must fund from your own money. Shortening it releases cash without selling anything more.
Why it explains so many failures. Growth increases every component: more stock, more customers owing you money. Working capital requirement scales with revenue, so doubling sales can double the cash trapped in the business — precisely when you are least able to spare it.
Some businesses have negative working capital, and it is a powerful advantage. Supermarkets and subscription businesses collect from customers before paying suppliers, so growth generates cash rather than consuming it. This is a structural feature worth understanding when comparing business models.
What actually improves it:
Invoice promptly. A surprising proportion of late payment begins with late invoicing.
Shorten payment terms, and enforce them — chasing is not rude, it is the job.
Take deposits or stage payments, which is the single largest lever for service businesses.
Reduce stock holding, without creating stockouts.
Negotiate supplier terms, and use the full period offered.
Invoice finance and overdrafts bridge the gap at a cost, and are a symptom rather than a solution if permanently required.
General information, not financial advice.