Tightening DSO, DPO and DIO Without Straining Relationships

The fastest lever for reducing days sales outstanding is usually invoicing discipline: send the invoice the moment work is delivered rather than batching it, and follow up on a set cadence rather than an ad hoc one. Offering a small early-pay discount to customers can also pull payment forward, mirroring the same annualized-return logic that applies to your own payables.

Where companies overreach is aggressive collections language or shortened terms applied uniformly across all customers, including the reliable, long-tenured ones who never needed the pressure. Segment your collections approach by actual payment history, not by treating every customer as a collections risk.

Extending days payable outstanding by simply paying vendors later than agreed terms, without renegotiating those terms, is the version that damages relationships and can put you at the back of the line during a supply shortage. The sustainable version is renegotiating stated terms upfront, moving from net 15 to net 30 with a vendor, rather than quietly stretching payment beyond whatever the agreement says.

Payables days norms vary a lot by industry, from around two to three weeks in fast-turnover sectors to closer to two months in some services and healthcare-support segments¹, so benchmark your DPO against your actual industry rather than a generic target that might be unrealistic or unnecessarily conservative for your specific business.

Reducing days inventory outstanding means holding less cash tied up in unsold inventory, but push it too far and you risk stockouts that cost you sales and customer trust, which is a worse outcome than the working capital you freed up. The right target depends on your specific demand predictability: a business with steady, forecastable demand can run leaner inventory than one with volatile or seasonal demand.

Track stockout incidents alongside DIO as you tighten it, so you catch the point where further reduction starts costing more in lost sales than it saves in working capital.

DSO plus DIO minus DPO gives you the cash conversion cycle, the number of days between paying cash out and collecting cash in, and it's worth tracking as a single trend rather than optimizing the three components in isolation. A company that shortens DSO by five days but extends DIO by eight days hasn't actually improved its cash position, even though one metric alone looks better.

Review the combined cycle at least quarterly, and treat an improvement in one component that's offset by a worse trend in another as a wash, not a win.

How aggressively you should optimize working capital depends partly on how much runway pressure you're under. A company with a higher burn multiple gets a bigger relative benefit from freeing up cash through the working capital cycle than one that's already close to breakeven, since every day of cash conversion cycle improvement extends runway further for a company burning faster². Use that as your prioritization signal for how hard to push, rather than chasing a generic "best practice" number pulled from a different kind of business.

Say your DSO is 45 days, your DIO is 30 days, and your DPO is 25 days, which puts your cash conversion cycle at 50 days, the time between paying your own costs and collecting from your customers, and say better invoicing discipline then shaves five days off that DSO while DPO and DIO stay flat, shortening the cycle to 45 days. That kind of measurable progress is something you can point to directly in a board update, rather than a vague claim that collections have gotten better.

Apply the three levers with these guardrails:

• Track DSO plus DIO minus DPO as one cash conversion cycle trend, not as three separate numbers.
• Segment collections by payment history, so reliable long-tenured customers aren't pressured like slow payers.
• Renegotiate vendor terms upfront instead of quietly paying later than agreed, which damages trust.
• Set inventory targets from how predictable your demand is, so leaner stock doesn't cause stockouts.