The 80/20 problem procurement can't shake
Most companies run tight controls on their biggest purchases: raw materials, logistics contracts, major software licenses. Then there is everything else. Fairmarkit, a Boston-based procurement sourcing vendor, describes the pattern this way: tail spend typically makes up around 80% of an organization's purchase transactions and 80% of its suppliers, while accounting for only about 20% of total spend value. Thousands of small, scattered buys, individually unremarkable, that add up.
Tail spend is not the same problem as maverick spend, though the two get confused. Maverick spend is a control failure: someone buys from a supplier outside an approved contract. Tail spend is a volume problem: purchases too small or too infrequent to ever get strategic sourcing attention in the first place, whether or not they broke a rule. A one-off $400 software trial and a repeat $3,000 freelance design invoice can both be fully compliant and still sit outside procurement's view.
Why so much of it stays invisible
New research from Ardent Partners, sponsored by GEP and based on a survey of 311 CPOs and senior procurement leaders conducted between January and March 2026, found that the average organization has 69.3% of its total spend under active procurement management. Top-performing organizations manage 90.2%. That roughly 20-point gap is not evenly spread across categories. It concentrates in the long tail: departmental subscriptions, contractor invoices, one-time equipment purchases, anything routed around a purchase order because the dollar amount did not seem worth the process.
The gap has persisted because the math used to make ignoring it rational. Running a formal sourcing event for a $600 purchase can cost more in staff time than it saves. That calculation shifts once automation lowers the cost of touching each transaction, which is what has pulled tail spend from a footnote into its own software category.
Three ways vendors attack it
Spend analytics and classification tools work retroactively. They pull transaction-level data from the ERP or procure-to-pay system and use machine classification to show where money actually went, by category, supplier and business unit, surfacing spend that was never formally sourced. Coupa built this into its platform through its 2017 acquisition of the UK analytics firm Spend360. Microsoft made a similar bet in 2021, acquiring the Seattle startup Suplari and folding its spend intelligence technology into Dynamics 365.
Guided buying, built into procure-to-pay platforms, works at the point of purchase instead. It routes an employee toward an approved supplier or existing contract before a new tail-spend transaction gets created, rather than cleaning it up afterward.
A third category is purpose-built tail spend marketplaces. Fairmarkit, founded in 2017, runs automated RFQs and reverse auctions specifically for the lower-dollar purchases that would never justify a category manager's time under the old model, batching similar small buys into events a sourcing team can actually run.
What to look at when buying
The definition of "tail" matters more than it sounds. Some tools set a fixed dollar threshold, others use transaction frequency or category rules, and the choice changes what the tool will and won't touch. Ask a vendor to show classification accuracy against your own chart of accounts and commodity taxonomy, not a benchmark dataset from another customer. Check integration depth with the existing ERP or procure-to-pay system; a tail spend tool that becomes a second system of record creates its own reconciliation problem. And ask how savings get tracked. Identifying an opportunity and realizing it are different things, and a tool that only reports the former is reporting potential, not results.
Where it commonly goes wrong
Deloitte's analysis, cited by Ivalua in an April 2026 guide, puts the total prize for fixing tail spend at 5% to 20% of the spend in scope, a wide range that reflects how differently organizations execute on it. The most common failure is treating tail spend as a project with an end date rather than a standing discipline. "Effective tail spend management is an ongoing discipline," Arnaud Malardé, a director at Ivalua, said in a July 2026 interview, noting that new tail spend forms continuously as departments buy, cancel and rebuy small-dollar services.
Teams that run a single cleanup, count the savings, and move on tend to find the same volume of unmanaged spend has regrown within a year or two. The tools above only hold their value if someone keeps using them after the first sourcing event ends.
Sources
- GEP, "How CPOs Measure Procurement Success" (Ardent Partners/GEP survey of 311 CPOs, Jan-Mar 2026) - https://www.gep.com/blog/mind/how-cpos-measure-procurement-success
- Ivalua, "Tail Spend Management" - https://www.ivalua.com/blog/tail-spend-management/
- EME Outlook, "Effective Tail Spend Management is an Ongoing Discipline: Arnaud Malarde, Ivalua" - https://www.emeoutlookmag.com/industry-insights/effective-tail-spend-management-is-an-ongoing-discipline-arnaud-malarde-ivalua
- Fairmarkit, "What Is Tail Spend and How Can We Manage It?" - https://www.fairmarkit.com/blog/what-is-tail-spend-and-how-can-we-manage-it
- Coupa Newsroom, "Coupa Acquires Spend360 to Modernize Processes for Data Analysis" - https://www.coupa.com/newsroom/coupa-acquires-spend360-modernize-processes-for-data-analysis/
- Microsoft Dynamics 365 Blog, "Microsoft Acquires Suplari to Strengthen Business Insight for Finance and Procurement Leaders" - https://www.microsoft.com/en-us/dynamics-365/blog/business-leader/2021/07/28/microsoft-acquires-suplari-to-strengthen-business-insight-for-finance-and-procurement-leaders/