Working Capital: How Much Cash Does Your Business Actually Need to Operate?

The Working Capital Gap Most Owners Miss#

You sign a £180,000 annual contract with a new corporate client. Brilliant news. The contract starts in August. You invoice monthly, 30-day terms. Your first invoice is September 1st for August's work. Payment arrives October 1st. But the staff delivering the contract need paying every two weeks starting in August. The materials and software licences were due upfront. By October 1st, you've spent £32,000 and received £0 from the new client. That £32,000 gap is working capital — and it can break a business that signed a contract it should have celebrated.

Calculating Your Working Capital Requirement#

The formula: Working Capital = Current Assets − Current Liabilities. Current assets: cash in bank, money owed to you (debtors), and stock. Current liabilities: money you owe suppliers (creditors), tax due, and short-term loan repayments. If your debtors total £45,000 (customers who owe you money) and your creditors total £28,000 (suppliers you owe), your net working capital is £17,000. That £17,000 needs to be funded by cash in the bank. If your bank balance is £12,000, you have a £5,000 working capital deficit — meaning you're relying on cash coming in from debtors before creditors demand payment.

The Working Capital Cycle in Plain English#

Cash → you buy stock or pay staff → goods or services delivered → you raise an invoice → customer pays → cash back. The length of this cycle — from cash out to cash back — is your cash conversion cycle (CCC). A café with no credit sales has a CCC of zero (cash straight back). A manufacturer selling on 45-day terms with 30-day stock holding and 20-day creditor terms has a CCC of 55 days (30 + 45 − 20). Every day in the CCC is a day your cash is tied up in the business. Shortening the CCC by 10 days on £1m turnover frees up £27,400 of cash — without borrowing anything.

Strategies That Reduce Working Capital Requirements#

Four levers: (1) Collect faster — invoice immediately, offer early payment discounts, chase overdue accounts actively. (2) Pay later — negotiate extended payment terms with suppliers (30 days → 45 days). (3) Hold less stock — tighter reorder points, faster-turning product selection, JIT where possible. (4) Get deposits — requiring 30–50% upfront from customers on large orders eliminates the gap on those projects. AskBiz tracks your debtor days, creditor days, and stock days automatically — showing you your actual CCC and how it compares to your sector.

How Much Working Capital Buffer Should You Hold?#

As a rule of thumb, hold at least one full CCC worth of cash as a buffer above your operating minimum. If your CCC is 45 days and your daily operating cost is £800, you need £36,000 in reserve to absorb a full cycle disruption (delayed payment, unexpected cost, slow month). Most SMBs hold far less. The businesses that sail through a slow January or a late-paying client are the ones who treated working capital as a priority, not an afterthought. AskBiz models your buffer requirement and shows how it changes as revenue grows.

• Working capital is the cash tied up in running your business day-to-day — the money you've spent but haven't yet collected.
• A retail shop buying £30,000 of stock on 30-day supplier terms but selling on immediate payment has a very different working capital need to a B2B services firm invoicing on 60-day terms and paying staff weekly.
• AskBiz calculates your working capital requirement and shows how it changes as your business grows — before the bank has to explain it to you at a difficult meeting.