Syntec index for December 2025

The revised Syntec index (base 100 in 1961) for December 2025 was published on January 30, 2026.

The value of the Syntec index for December 2025 is 322.6, up from 314.8 in December 2024, giving an annual rate of 2.48% over 12 months. The December index is down 0.15% compared to the previous month (323.1 in November 2025).

Contents

Table of changes in the Syntec index for December 2025

	December 2025 Syntec Index	November 2025 Syntec Index	December 2024 Syntec Index
Syntec index value	322.6	323.1	314.8
Change in % from the base		Up 0.15%	Up 2.48%

Syntec Index December 2025

The official source is Syntec Federation (not INSEE).

The value for December 2025, to be used for contracts signed before December 2022 (revised index corrected by the connection coefficient), is 316.6. Our Syntec Index 2025 table has been updated here:

Revised Syntec Index corrected for the adjustment coefficient and monthly and annual percentage changes:

Publication dates of the revised Syntec Index 2025

All revised and historical Syntec index values for 2025

The Syntec index reflects the evolution of salary costs (mainly intellectual services) of companies in the professional branches of the Syntec Federation:

“Syntec IT“,
“Syntec Engineering“,
“Syntec Group of Study and Consulting Unions“.

It is mainly used to update the financial clauses of engineering, contracted personnel, maintenance, and IT contracts. Its value is calculated each month based on a survey of representative companies.

Publication of the Syntec Index December 2025 — Publication on January 30, 2026, of the Syntec index for December 2025

The Ministry of Economics and Finance in France has recognized the Syntec index since December 11, 1974. It is updated and published monthly, typically at the end of each month, with a one-month lag. The following index will be released: the Syntec January 2026 index, expected around February 27, 2026.

For companies in the technology and services sectors, the Syntec Index is a crucial tool for ensuring fair contracts that reflect actual costs. It provides an objective basis for price reviews and helps protect against unforeseen cost variations.

Frequently Asked Questions (FAQ) on the Syntec Index of December 2025

What is the Syntec Index?

The Syntec Index is a French economic indicator primarily used to adjust contract prices for intellectual services, particularly in engineering, IT services, consulting, and research and development. It is used, in particular, to adjust the prices of services on long-term contracts to account for cost fluctuations.

What is the value of the Syntec index for December 2025?

The value of the Syntec index for December 2025 is 322.6. It is up 2.48% over the past year (as of December 2024) and down 0.15% compared to November 2025 (the previous month). The revised index, corrected for the connection coefficient, stands at 316.6.

How do you integrate the Syntec Index into a contract?

To integrate the Syntec Index into a contract, a price adjustment clause must be included that specifies that prices will be periodically adjusted based on changes in the Syntec Index. The adjustment frequency and the calculation formula must also be defined.

Can the Syntec Index decrease?

Yes, although rare, the Syntec Index can decrease if the costs of intellectual services decrease. This can occur when there are significant reductions in salaries, social charges, or operating costs for the relevant companies. It may decrease from one month to the next, but rarely in the annual trend.

Are there alternatives to the Syntec Index?

Economic indices, such as the Consumer Price Index (CPI) and the Producer Price Index (PPI), can be used to adjust contract prices. However, the Syntec Index is designed explicitly for intellectual services and is most relevant to this sector.

When is the Syntec Index published?

The Syntec Index is published monthly, usually at the end of each month, with a one-month lag.

Syntec Index History

Find all the values of the Syntec index since 2014:

Syntec Index History:

History of the Syntec index, a tool for measuring labor costs

What’s your opinion on the evolution of the Syntec index?

Tell us in the comments. THANKS.

The Syntec Index for December 2025 has been released