What is Price Indexation Clause?

Price indexation clauses appear in virtually every multi-year service contract. The supplier's reasoning is straightforward: wage and material costs rise every year and they do not want to see their margin eroded. From your side, an uncapped indexation clause means prices can rise each year without negotiation or explicit notification — beyond a revised invoice.

Several indices are used. The most common is the national consumer price index (CPI), though suppliers in construction, technical services, and cleaning often use sector-specific wage cost indices that move differently from general inflation. In 2022 and 2023, some sector indices rose by eight to twelve percent, leading to contractual price increases that many customers did not anticipate.

Three points are relevant when negotiating an indexation clause. First, the choice of index: is the index being applied actually representative of the cost drivers for this specific service? Second, the frequency: annual adjustment is standard; more frequent adjustment is unusual and worth challenging. Third, the cap: a maximum percentage per year — "indexation is capped at three percent annually" — limits exposure in periods of elevated inflation.

You do not need to refuse an indexation clause outright. Suppliers will almost always insist on one. What you can negotiate is a realistic ceiling and a requirement that the indexation is applied transparently and in line with the clause.

On a service contract worth £24,000 per year, an annual indexation of five percent produces an additional £1,200 in year one, rising cumulatively each subsequent year. Across ten contracts with uncapped indexation clauses, the unbudgeted cost increase becomes material.

The risk is invisibility. The price increase is applied automatically, the revised invoice arrives, and the payment is processed without comparison to the original contract price. Recording indexation clauses explicitly in your contract register — noting the index used, the agreed cap, and the price at signing — makes it straightforward to verify every invoice and challenge any application that exceeds what was agreed.