Outsourcing Tail Spend or Optimizing It Internally?

Internal optimization is enough as long as Tail Spend can be consolidated, fitted into an existing catalog, or approved more simply below a de minimis threshold. Once one-off requirements become too numerous, too irregular, or too varied to fit into one of these three tracks, a single external creditor becomes the more effective answer. Five questions show which side a company actually falls on.

Both paths start at the same point: the recurring onboarding of new suppliers for requirements that rarely occur a second time. Internal levers ease this burden. It doesn't disappear entirely, though, if the number of one-off creditors stays structurally high.

At a Glance

• Internal levers such as de minimis thresholds, consolidation, and catalog systems work as long as one-off requirements stay rare, predictable, and catalog-ready.
• As the number and irregularity of one-off creditors rise, the advantage shifts toward a single external creditor.
• Five questions on creditor count, order value, catalog fit, predictability, and capacity show which model actually fits.

When Internal Optimization Still Pays Off

Three internal levers work as long as the requirement stays reasonably predictable. A de minimis threshold simplifies approval below a set order value. That saves time, especially for small amounts. The supplier still has to be onboarded.

Consolidation works where several requirements from the same department can be shifted to a fixed date, for example once a week. An existing catalog system additionally covers any requirement that fits into a pre-curated list. No new creditor arises for this.

How these and two further strategies work in detail, and where they reach their limits, is covered by the in-depth comparison on process optimization for one-off requirements. For a predictable, rare, and catalog-ready requirement, the three levers above remain the more cost-effective choice.

This makes it possible to check, before any decision, how far the known Tail Spend Management models already apply within the company.

When an External Creditor Is the Better Choice

All three internal levers assume that the requirement can be classified somewhere: under a threshold, into a batch date, or into a catalog. A genuine one-off requirement lacks exactly this precondition, because it arrives unannounced, in varying form, and without a known supplier. None of it can be classified in advance. No pattern fits twice.

As the number of such cases grows, so does the number of new creditors in the ERP system, regardless of how lean the internal approval process is designed. Approval alone no longer helps at that point.

Beyond a certain scale, the recurring setup alone costs more than any optimization elsewhere can save. That shows up measurably in the process costs per order that recur with every new creditor. At that point the real question shifts. It's no longer about how to speed up the existing process, but about who instead consolidates the many different suppliers.

The Decision Tree: Five Questions Before Choosing a Model

Five questions structure the decision, regardless of industry or company size. Each answer shifts the result toward internal optimization or an external creditor.

1. How many new creditors arise per year from one-off requirements alone? If only a few, an internal de minimis threshold usually still carries the load. Once several dozen accumulate, the setup effort weighs structurally heavier than any simplification of approval.
2. Does the typical order value fall below or above the company's own de minimis threshold? Below it, a full review remains disproportionate regardless of the chosen model. Above it, a closer internal case-by-case review is at least worthwhile.
3. Can the requirement be fitted into an existing catalog or framework agreement? If it fits, the internal structure remains the more cost-effective choice. If it doesn't fit, as with most genuine one-off requirements, a catalog no longer offers any advantage.
4. Can the order wait for a fixed batch date? If yes, consolidation noticeably lowers the effort per line item. If no, for example with a broken spare part, the batch date gets in the way of the order's actual purpose.
5. How much free capacity does procurement have for supplier vetting and invoice control? If capacity exists, internal levers carry the load a while longer. If it's exhausted, every new supplier extends the waiting time for all other transactions as well.

If the answers lean toward creditor count, poor catalog fit, and exhausted capacity, the external creditor pays off, on the numbers, almost always more than another round of internal optimization.

What the Wrong Choice Costs

A maintenance department needs a replacement pump on short notice for around €350, an illustrative example value. If the decision falls internally because the de minimis threshold formally allows it, a new creditor, a new review, and a separate invoice still arise, just with simplified approval. In the end, the same baseline of process costs remains. Just better hidden.

The full cost formula behind this can be worked out concretely with a company's own numbers and prepared for the CFO. It covers setup cost per creditor, process cost per order, and invoice review across changing invoice issuers. What matters most to the CFO in the end is one number: the annual total of setup and process costs across all one-off creditors.

Who Actually Runs the External Creditor

What remains open is who actually runs this external creditor day to day, once a company decides in its favor. Someone has to manage it. Pedlar operates this model as a managed service. For the internal side, nothing changes about budget responsibility or approval levels. The difference is purely structural. Only the recurring onboarding of new suppliers disappears, because every further order runs through the same, already-established creditor.

Which Model Fits Which Areas

Both paths don't exclude each other. Standardized, predictable requirements are usually best kept in the internal structure, as long as a catalog or framework agreement applies. That rarely changes. The external creditor takes over the rest in a targeted way: spare parts, custom fabrications, trade-show requirements, and other needs without a fixed supplier. That's exactly where its strength lies.

The effect shows most clearly at industrial companies with multiple sites and departments, because new, different one-off creditors keep accumulating there. At a single site with manageable requirements, by contrast, internal optimization often remains sufficient for longer.

Frequently Asked Questions

Do Internal Optimization and an External Creditor Exclude Each Other?

No. The two complement each other well. A catalog for predictable standard requirements and an external creditor for the unstructured rest can be combined without issue.

Does Procurement Lose Control Over the Order When It Outsources the Creditor?

No. Approval levels, budget responsibility, and compliance requirements stay with the company. The external creditor handles the operational processing, not the decision.

Does Switching to an External Creditor Require New Software?

No, that's not necessary. Software changes nothing about that. Ordering and invoicing can be handled the classic way, by email; a punchout integration to an existing system can be added if needed.

Find out how the Single Creditor Model makes the choice between internal optimization and an external creditor clear: Schedule a call →