15 Oct Contract Deviations: How Small Changes Can Unlock Big Costs

No fleet ever runs exactly as planned. Mileage changes, vehicles come off-fleet earlier than expected, and contracts are adjusted mid-term. Suppliers refer to this as contract deviation, and it’s one of their most profitable levers.

Common Triggers

• Adjustments – When usage strays 10–20% from agreed parameters, suppliers reset contracts, usually in their favour.
• Excess mileage – End-of-contract charges vary widely between suppliers and are often inflated.
• Early termination – Opaque penalties can lock organisations into contracts that no longer meet their needs.

The Risk for Procurement Leaders

Suppliers often control the reset methodology, not the market. Without predefined formulas and rules, procurement is left exposed to supplier-driven recalculations. Over the life of a fleet, this can add up to significant and unpredictable costs.

What To Do Instead

• Define deviation rules upfront – Remove ambiguity by fixing adjustment criteria in contracts.
• Standardise excess mileage rates – Ensure fairness and transparency in both charges and credits.
• Model termination scenarios – Understand and negotiate clear, equitable exit formulas before signing.

Contract deviations are inevitable,  but excessive costs don’t have to be. With clear governance and contractual controls, procurement can keep flexibility without funding supplier profit.

Learn more about how to manage deviation costs and control other trapdoors in our ebook, Control the Contract, Control the Cost.