Tail Spend Costs: The Business Case for Consolidation

The business case for consolidating tail spend comes down to a single formula. It has three items: the number of one-off creditors times setup costs, the number of orders times process costs, and the extra effort for invoice review when the invoice issuer keeps changing. The formula needs nothing more.

Putting even a rough number on these three items shows immediately where the money actually goes. It doesn't disappear into the goods value of the individual order, but into repeating the same administrative steps for an ever-changing set of suppliers. The effect hits every order. That's exactly the calculation a CFO needs before deciding on consolidation. Three numbers are enough for that.

The Cost Formula: What Tail Spend Actually Costs Procurement

Anyone who approaches Tail Spend Management systematically usually already knows the three cost drivers from daily practice. Every procurement professional knows two of them. Every new one-off creditor incurs setup costs: review, approval, and setup in the ERP system, regardless of how often that supplier actually places orders later on.

Every single order incurs process costs. Whether it's the first or the tenth order with that creditor makes no difference. The amount stays the same. You can work out your own figure using the methodology described in the article on measuring process costs, without needing an external study or an extensive internal survey.

Third, there's the extra effort for invoice review. That happens whenever an invoice arrives from a previously unknown invoice issuer. Accounts payable then has to check bank details, tax ID, and compliance information all over again, even though the actual order was approved long ago. That costs extra time.

A Sample Calculation for the CFO

A rough sample calculation makes the difference tangible, even if the exact numbers at your own company differ. Let's assume 200 one-off creditors and 250 orders per year. Setup costs run €150 per creditor. For small one-off requirements, €500 process costs per order serves as an assumption, and invoice review costs an additional €40 per new creditor. Both figures are illustrative, not external benchmarks.

Before consolidation, that adds up to €30,000 in setup costs, €125,000 in process costs, and €8,000 in invoice review, together €163,000 per year. After consolidation through a single creditor, setup happens only once. Invoice review disappears completely. In this assumption, pure process costs drop by up to 85%.

Broken down, it's still the same cost stack of setup, process, and invoice review, just with a single creditor behind it. The total savings actually come in higher than the assumed 85%, because setup costs and the extra effort for invoice review disappear completely once the same creditor handles every further order. That combination is where the real lever sits.

Anyone who needs their own figure can simply replace the example values with their own creditor and order numbers. Setup and invoice review are often missing from calculations that focus only on process costs per order.

What Consolidation Actually Removes, and What It Only Shifts

Not every measure that lowers costs on paper actually removes one of the three items. De minimis thresholds simplify approval. The creditor still has to be set up, the invoice still has to be reviewed. The most expensive steps remain. For orders under €500, this weighs especially heavily: as the sample calculation above shows, process costs there quickly come close to the value of the goods itself.

Batch orders only shift the timing, and framework agreements only help with recurring requirements. Both approaches merely push setup costs into the future. They don't remove them. Only consolidation through a single creditor removes setup entirely as its own cost item from the formula.

How to Build the Slide for the CFO

A convincing slide needs no more than three elements:

1. The current cost formula with your own, roughly measured values for setup costs, process costs, and invoice review.
2. The target calculation after consolidation, using the same formula but with only one creditor.
3. The difference in euros per year, not in percent, because a CFO thinks in amounts.

It's important to show all three items separately, instead of hiding them inside a single process-cost metric. That way, the CFO immediately sees which lever delivers which share of the savings, and can check the assumptions independently. Every number stays verifiable. A single sample calculation is usually enough for this; a full process-cost analysis isn't necessary at this stage.

Who Actually Runs the Single Creditor

The formula shows what's possible, but it doesn't answer who actually runs the single creditor day to day. Pedlar operates this model as a managed service.

A single provider immediately raises the dependency question for the CFO: what happens on a switch, and who decides on budget and approval? Approval levels and budget ownership stay anchored in your own ERP system; the provider takes on only the operational processing behind it. On an exit, the only change to the cost formula is that the creditor has to be set up again, once, not for every single order.

Which Companies the Business Case Works For

The business case pays off wherever a large number of one-off creditors meet a moderate but steady order volume. Typical examples are industrial companies with multiple sites and specialist departments, each ordering their own spare parts or specialized requirements. The lever grows with every additional site.

The more creditors are created per year, the bigger the lever from the formula, because setup costs are incurred per creditor, regardless of how many orders actually follow later on.

For stable, plannable standard requirements, a catalog system usually remains the better fit. There, the catalog wins. The business case for a single creditor specifically targets the rest: the orders that never have a fixed supplier.

Frequently Asked Questions

How do I determine my own setup costs per creditor?

For the last ten creditors you set up, record the time spent and the roles involved in review, approval, and setup, then multiply the average by your fully loaded hourly rate.

Why isn't the process-cost metric alone enough for the business case?

It shows only one of the three cost drivers. Setup costs and the extra effort for invoice review come on top, and they disappear entirely under consolidation, not just partially.

How large is the saving from consolidation in the example?

In the sample calculation above, pure process costs drop by the assumed 85%. Because setup costs and invoice review disappear on top of that, the total savings are in this case even higher.

What belongs on the slide if my company doesn't have any numbers yet?

Even without complete data, a rough estimate clearly labeled as a sample calculation is usually enough to show the direction of the decision.

At a Glance

• Three items make up the total cost of tail spend: setup costs per creditor, process costs per order, and invoice review for changing invoice issuers.
• De minimis thresholds, batch orders, and framework agreements shift individual cost items around. None of them removes any completely.
• Only a single creditor lowers all three items at once.

Find out how the Single Creditor Model puts hard numbers behind your business case for consolidating tail spend: Schedule a call →