The revised Syntec index (base 100 in 1961) for September 2025 was published on October 31, 2025.
The value of the Syntec index for September 2025 is 321.7, representing a 7.2-point increase from 314.5 in September 2024, an annual rise of 2.29% over the 12 months. It’s up +0.19% compared to the previous month (321.1 in August 2025).
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Table of changes in the Syntec index for September 2025
| September 2025 Syntec Index | August 2025 Syntec Index | September 2024 Syntec Index | |
| Syntec index value | 321.7 | 321.1 | 314.5 |
| Change in % from the base | Up 0.19% | Up 2.29% |
The official source is Syntec Federation (not INSEE).
The value for September 2025, to be used for contracts signed before September 2022 (revised index corrected by the connection coefficient), is 314.6.
Our Syntec Index 2025 table has been updated here:
Revised Syntec Index corrected for the adjustment coefficient and monthly and annual percentage changes:
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.
The Ministry of Economics and Finance in France has recognized the Syntec index since November 11, 1974. It is updated and published monthly, typically at the end of each month, with a one-month lag. The following index to be released is the Syntec October 2025 index, which will be released around November 28, 2025.
For companies in the technology and services sector, the Syntec Index is a crucial tool for ensuring fair contracts that align with 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 September 2025
Syntec Index History
Find all the values of the Syntec index since 2014:
Syntec Index History:
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