Every procurement team has negotiated favorable contracts with preferred vendors. And every procurement team has watched employees buy from other vendors anyway. This is called maverick buying or off-contract spend, and it’s one of the most persistent and underquantified sources of cost leakage in enterprise finance.
The direct cost is straightforward: purchases made outside of preferred vendor contracts don’t benefit from negotiated pricing. If your preferred vendor contract gives you 30% off list price and an employee buys from a non-preferred vendor at list price, that 30% premium is pure waste.
The indirect costs are less visible but often larger. Off-contract spend fragments spend across more vendors, reducing your leverage with preferred vendors. It creates accounts payable complexity as new vendors need to be onboarded. It may expose the organization to vendors who haven’t gone through security or compliance review. And it signals to preferred vendors that your volume commitments may not materialize, which weakens your position at the next negotiation.
How much off-contract spend exists?
Industry benchmarks suggest that 20–40% of enterprise spend occurs off-contract. The wide range reflects the maturity of the organization’s procurement practices — companies with strong purchasing controls at the low end, companies with minimal procurement governance at the high end.
For a company spending $50M annually on non-payroll operating expenses, 30% off-contract means $15M in spend that isn’t leveraging negotiated terms. If negotiated terms average 20% better than off-contract prices, the recoverable value is $3M per year.
The challenge is that this spend is typically invisible as a category. AP systems record who was paid; they don’t record whether the vendor was preferred, what contract terms applied, or what the price differential was. Quantifying off-contract spend requires matching transaction data against contract records — work that most finance teams don’t currently do.
Why employees buy off-contract
Understanding the root causes prevents solutions from being purely punitive.
Preferred vendor can’t fulfill the requirement — The most legitimate case. A preferred vendor for office supplies doesn’t carry a specific specialty item. A preferred IT vendor doesn’t carry a specific brand the team needs. Off-contract spend here is filling a real gap in the preferred vendor network.
Preferred vendor process is too slow — Getting something from a preferred vendor requires a PO, which requires an approved vendor relationship, which requires going through procurement. Under time pressure, employees find a faster path. The off-contract vendor can ship tomorrow; the procurement process takes two weeks.
Employees don’t know the preferred vendor — Preferred vendor programs that aren’t communicated clearly produce off-contract spend from employees who aren’t trying to circumvent anything — they just don’t know the preferred vendor exists. This is especially common for newer employees and for spend categories that aren’t frequently used.
Preferred vendor relationship is poor — If the preferred vendor delivers poor service, employees will work around them. The contract says one thing; the operational reality drives behavior in another direction.
Category not covered by preferred vendor program — Many enterprise vendor programs cover a limited set of spend categories. Spend in uncovered categories defaults to whatever vendor the employee can find.
Measuring and categorizing your off-contract spend
A meaningful off-contract spend analysis requires three datasets:
Transaction data — Your AP and P-card transaction history, ideally with GL coding and cost center.
Vendor master — Your list of approved and preferred vendors, ideally with the spend category each covers.
Contract data — Your active vendor contracts, with the categories they cover, term dates, and key commercial terms.
The analysis: join transaction data to vendor master, identify transactions with non-preferred vendors, and categorize by whether a preferred vendor exists for that category. This produces four buckets:
- Preferred vendor used correctly — On-contract, as intended
- Preferred vendor available but not used — The recoverable maverick spend
- Non-preferred vendor, category covered — Off-contract, a preferred vendor exists
- Non-preferred vendor, category not covered — Off-contract, no preferred vendor covers this need
Buckets 2 and 3 are the action items. Bucket 4 is the signal that your preferred vendor program has coverage gaps.
Reducing off-contract spend without making procurement the enemy
Purely restrictive approaches — blocking non-preferred purchases, requiring procurement approval for anything off-contract — are effective at reducing off-contract spend and also effective at creating an adversarial relationship between procurement and the rest of the business. The business learns to route around procurement; procurement becomes a bottleneck rather than a partner.
The approaches that work long-term:
Make the preferred path faster than the off-contract path — If procurement can get something from a preferred vendor faster than an employee can buy it directly, the compliance problem largely solves itself. This means investing in punch-out catalogs, streamlined PO processes, and procurement team responsiveness.
Close coverage gaps — When off-contract spend analysis reveals categories without preferred vendors, add them. A procurement team that responds to business needs builds credibility; one that focuses only on control loses it.
Fix the preferred vendor relationships that aren’t working — Off-contract spend in categories with preferred vendors is often a signal about vendor performance. If employees are consistently buying from an alternative, find out why before assuming it’s a compliance issue.
Communicate clearly and repeatedly — Preferred vendor programs are only effective if people know about them. Onboarding materials, annual reminders, and a simple way to answer “who is the preferred vendor for X” go a long way.
Set category-specific targets, not blanket policies — Off-contract spend reduction is more tractable when it’s addressed category by category. Setting a goal of “reduce IT hardware off-contract spend from 35% to 15% in the next two quarters” is more actionable than a general mandate.
The contract compliance conversation
Off-contract spend analysis often reveals something else: spend that is nominally on-contract but not actually at contract terms. An employee uses a preferred vendor but doesn’t cite the contract, doesn’t get the negotiated pricing, and pays list rate anyway. This is a different problem from maverick buying — the vendor relationship is there, but the commercial terms aren’t being enforced.
For large contracts with volume-sensitive pricing, this is worth auditing. Pull a sample of transactions with preferred vendors and check whether the prices paid match the contracted rates. Discrepancies are recoverable through vendor credit requests and worth quantifying.
CostDefender matches your transaction data against contract records to surface off-contract spend by category and vendor — giving procurement and finance the shared visibility to prioritize compliance efforts.