The Cash Conversion Cycle Playbook: find the working capital already sitting inside your business

There is a specific kind of business failure that confuses everyone involved. Revenue is growing. Gross margin is fine. The P&L says the company made money last quarter. And the bank balance keeps going down.

What is happening is almost always the same thing. The business pays for its inputs before its customers pay for its outputs, and the gap between those two events is being funded out of the bank account. Grow the revenue and you grow the gap. This is why fast-growing profitable companies die, and it is why “we need more sales” is so often the wrong answer to “we are out of cash.”

The gap has a name and a formula. It is the cash conversion cycle, and it is measured in days. This playbook shows you how to calculate yours from numbers you already have, how to read what it tells you, the four levers that shorten it, the scripts to actually pull them, and the ways each one goes wrong.

Step 1 — Calculate the number (30 minutes)

You need four figures, all from the last twelve months, all from your accounting system:

• Revenue
• Cost of goods sold (COGS)
• Average accounts receivable — take the balance at the start of the period and the end, and average them
• Average inventory, and average accounts payable, the same way

Then three ratios:

• DSO (days sales outstanding) = average receivables ÷ revenue × 365. How long customers take to pay you.
• DIO (days inventory outstanding) = average inventory ÷ COGS × 365. How long you hold stock before selling it. Service businesses: use work-in-progress, or unbilled delivered work, or zero if neither exists.
• DPO (days payable outstanding) = average payables ÷ COGS × 365. How long you take to pay suppliers.

Cash conversion cycle = DSO + DIO − DPO.

That is the number of days your own money is tied up in every turn of the business. Positive means you are financing your customers. Negative means your suppliers are financing you — which is the structural reason supermarkets and marketplaces can grow without raising capital.

A worked example

A distributor with £6m revenue, £4.2m COGS, average receivables of £1.15m, average inventory of £900k, average payables of £520k.

• DSO = 1,150,000 ÷ 6,000,000 × 365 = 70 days
• DIO = 900,000 ÷ 4,200,000 × 365 = 78 days
• DPO = 520,000 ÷ 4,200,000 × 365 = 45 days
• CCC = 70 + 78 − 45 = 103 days

Now the sentence that makes it real. At £4.2m of COGS, one day of cycle is roughly £11,500 of cash. That business has about £1.18m of its own money permanently parked in the cycle. Cutting 20 days releases roughly £230,000 — once, permanently, with no new customers and no new debt.

Write your own version of that sentence before you go any further: one day of my cycle is worth £X, and I am currently carrying Y days. Everything below is priced against it.

Step 2 — Find out which of the three is broken

The headline CCC tells you the size of the problem. It does not tell you where it is. Split it, then benchmark each component against your own past rather than against an industry table — the trend is far more informative than the level.

Pull DSO, DIO and DPO for the last eight quarters and chart them. You are looking for one of three patterns:

• DSO rising. Either your collections process has decayed, or you have started selling to larger customers who pay on their terms rather than yours, or your invoices are being disputed and nobody has told you.
• DIO rising. You are buying ahead of demand, your mix has shifted toward slower-moving lines, or you have dead stock you have not written off and are therefore still counting as an asset.
• DPO falling. Usually somebody started paying suppliers early to keep the peace, or you lost credit terms after a late payment and got moved to pro-forma.

One more cut, and it is the one that finds the money fastest: an aged receivables list sorted by value, not by age. In almost every business, more than half the overdue cash sits in fewer than ten invoices. Chasing the long tail feels productive and moves nothing.

Step 3 — The four levers

Lever 1: Invoice faster (the cheapest day you will ever buy)

Before you ask anyone to pay sooner, check how long it takes you to ask. The interval between delivering work and issuing the invoice is pure, self-inflicted DSO, and it is routinely 5–15 days in businesses that have never measured it.

Measure it: for the last 30 invoices, record delivery date and invoice date. If the median is above two days, you have found free cash. Fixes, in order of effort: invoice on delivery rather than on a monthly cycle; for project work, bill on milestone completion rather than at the end; and put invoicing on one named person’s calendar rather than leaving it to whoever remembers.

Also audit the invoice itself. An invoice missing a PO number, addressed to the wrong entity, or sent to a person rather than an accounts-payable inbox does not get paid late — it gets paid from the day it is correctly received, which is usually the day you chase it three weeks later.

Lever 2: Change the terms on new business, not the old

Renegotiating terms with an existing customer is a fight. Setting them correctly on the next contract is an administrative decision. Run every change through the new-business pipeline first and let the book reprice as it renews.

Three structures that work, in rough order of how hard they are to sell:

• Deposit on order. 25–50% upfront for anything with materials or subcontractor cost attached. Justified by input cost, not by trust, which is what makes it sayable.
• Milestone billing. Split a project into three or four billing points. Easier to agree than a deposit because the customer only pays for what has arrived.
• Shorter net terms. Net 14 instead of net 30. Most small and mid-size customers accept it if it is on the quote from the start.

The script for an existing customer, when you do have to have the conversation:

“We’re moving to net 14 across the board from the first of next quarter. You’re on net 45 today, so I wanted to give you the notice rather than have it turn up on an invoice. Is there anything in your process that makes 14 difficult? If your system needs a set day of the month, tell me and I’ll invoice around it.”

The last sentence does the work. Half of all late payment is not reluctance, it is a payment run on the 25th that your invoice keeps missing by two days. Ask when the run is and invoice to hit it.

Lever 3: Take the payables days you are entitled to

Not paying suppliers late — that is a different and much worse strategy that costs you priority, goodwill and eventually terms. This is about using the terms you already have. Businesses that pay everything the day the invoice arrives are donating free financing to their suppliers.

• Move from ad-hoc payments to a weekly payment run. This alone typically adds 3–5 days of DPO with zero relationship cost.
• Ask for terms on renewal of any significant supplier contract. On a contract renewal you have leverage you do not have at any other moment.
• Do the maths on early-payment discounts before taking them. 2/10 net 30 — 2% off for paying 20 days early — is an annualised return of roughly 37%. That is one of the best uses of cash available to you if you have the cash. If you are drawing on a facility at 9% to take it, take it. If taking it means you cannot make payroll, it is the most expensive 2% in the world.

Lever 4: Attack inventory by line, never in aggregate

“Reduce inventory 20%” is not an instruction, it is a wish, and the way it gets executed is by cutting the fast-moving lines that are easy to reorder while the dead stock sits untouched.

Instead, rank every SKU by turns — annual COGS for that line divided by average inventory value for that line — and look at the bottom quintile. For each one, exactly three options: discount it to clear, write it off and reclaim the space, or justify in writing why holding it is worth the cash. The written justification is the point; most dead stock survives because nobody has ever been made to defend it out loud.

Then fix the reordering rule that created it. Usually it is a minimum order quantity from a supplier that made sense at a volume you no longer do, or a safety-stock level that was set once and never revisited.

Step 4 — The failure modes

Four ways this goes wrong, all of them common:

• You buy DSO with margin. Offering 2% for early payment to fix a collections problem is paying roughly 37% annualised to avoid a phone call. Fix the process first; discount only when the process is clean and the customer is still slow.
• You stretch payables into a supply problem. Push DPO far enough and you lose priority on allocation, then you lose terms, then you are on pro-forma and your DPO is zero. The ceiling is your contractual terms, not your supplier’s patience.
• You cut inventory into stockouts. A lost sale costs the full gross margin; a carried unit costs the financing rate on its value. Below a certain point, cutting stock is the expensive option. Track service level alongside turns or you will optimise one into the ground.
• You improve the ratio without improving the cash. DSO falls because revenue rose while receivables stayed flat. DPO rises because COGS collapsed. The ratios are fractions and both ends move. Always check the absolute balances alongside the days.

Step 5 — Make it a standing number

This is a one-afternoon exercise that only pays if it becomes a monthly one. Put four lines on whatever dashboard you already look at — DSO, DIO, DPO, CCC — with the prior month and the same month last year beside each. Add one line underneath: cash value of one day. That converts a ratio nobody feels into a number everybody does.

Then give each component an owner. DSO belongs to whoever raises and chases invoices. DIO belongs to whoever buys. DPO belongs to whoever pays. An unowned metric drifts back within two quarters, without exception.

The 60-minute version

If you do nothing else this week:

1. Calculate DSO, DIO, DPO and CCC from your last twelve months. (20 minutes)
2. Divide annual COGS by 365 to get the cash value of one day. Write it somewhere you will see it. (2 minutes)
3. Check the median gap between delivery and invoice on your last 30 jobs. (15 minutes)
4. Sort aged receivables by value and call the top three. (20 minutes)
5. Move supplier payments to a weekly run. (3 minutes)

The cash you free this way is the cheapest capital available to you. It is already yours, it does not dilute anybody, it carries no interest, and nobody has to approve it.