Belgium has introduced major reforms to automatic wage indexation, and for the first time in decades the country’s celebrated inflation-proofing mechanism will not apply in full to every salary. A Programme Act adopted by Parliament at the end of May 2026 – published and in force since 1 June 2026 – temporarily caps indexation for employees earning more than €4,000 gross per month and pairs the cap with a brand-new employer social security contribution. This article explains how Belgian indexation normally works, what precisely has changed, how the sums are calculated, and what employers with staff or contractors in Belgium should be doing right now.
Belgium is one of very few countries in Europe – Luxembourg being the other notable example – where salaries rise automatically with the cost of living. The mechanism is anchored not in a single statute but in sectoral collective bargaining agreements concluded within joint committees. Wages are linked to the smoothed health index, a consumer price measure published monthly by Statbel that strips out alcohol, tobacco, petrol and diesel.
Each sector applies its own formula and calendar. Joint Committee 200, the largest white-collar committee, adjusts salaries once a year on 1 January. The chemical industry committees apply a 2% uplift each time a pivot index threshold is crossed, while others index quarterly, monthly or only up to a sectoral ceiling. The result is a patchwork of timings, but until now the principle was simple: when inflation rises, the whole salary follows, without negotiation and without employer discretion.
Although the coalition agreement of the De Wever government only committed to reviewing indexation by the end of 2026, Parliament moved faster. The Programme Act approved on 28 May 2026 and in force since 1 June 2026 introduces what is popularly known as the “cent index” (centenindex) – a temporary, targeted cap. The core rules are as follows:
The Act applies broadly: private and public sector alike, covering everyone within the Belgian social security system. Reference remuneration means the indexed fixed monthly basic salary under the applicable pay scale, or the contractual salary where no scale applies. A parallel measure caps indexation of pensions and social benefits at €2,000 gross per month.
Two moderation periods are foreseen. The first runs from 1 June 2026 until the 2% cap has been absorbed – with Belgian inflation currently around 3.4% a year, that is expected to take less than twelve months in most sectors. A second period starts, in principle, on 1 January 2028, by which point the €4,000 threshold itself will have been index-linked. Crucially, the reform does not abolish indexation or permanently rewrite any collective agreement: outside the moderation periods, the familiar sectoral mechanisms continue to operate.
Suppose an employee earns €10,000 gross per month and the applicable sectoral indexation rate is 2.2%. The table below contrasts the old and new outcomes:
| Element | Before the reform | Under the Programme Act |
| Indexation on first €4,000 | 2.2% = €88 | Capped at 2% = €80 |
| Indexation on remaining €6,000 | 2.2% = €132 | Suspended for the first 2%; only the 0.2% excess applies to the full salary = €20 |
| Total monthly increase | €220 | €100 |
| Monthly difference | – | €120 lower |
Because subsequent indexations are calculated on a lower gross figure, the effect compounds over an employee’s career with the same employer. HR services provider SD Worx has estimated the loss for someone on €5,000 gross at roughly €20 per month per capped indexation round – modest at first glance, but material once repeated in 2028 and carried forward through every later adjustment.
Employers do not simply pocket the savings. The Act introduces a special wage moderation contribution payable to the National Social Security Office (NSSO), designed to compensate the State for lost tax and social security revenue. Broadly, around half of the employer’s saving from restrained indexation is redirected to the Treasury, together with the corresponding employer contributions. The levy is collected alongside ordinary quarterly social security contributions, and non-payment attracts the usual sanctions. A consolidated wage moderation contribution follows once the moderating effect has been achieved. Notably, while the indexation cap itself is temporary, the contribution has no built-in end date; Royal Decrees are still awaited to settle the detailed calculation methodology.
One point catches many well-meaning employers off guard: voluntarily granting full indexation anyway is not a safe harbour. An employer that does so must still pay the new contribution on top of the higher salary, and risks infringing the Salary Moderation Act of 26 July 1996, which can trigger administrative fines. Generosity, in this instance, can be doubly expensive.
Because Belgian indexation follows sectoral calendars, the cap bites at different moments for different workforces. Employees in Joint Committee 200 received their full 1 January 2026 indexation untouched and will first feel the cap in January 2027. Sectors that index several times a year – monthly, quarterly or on each pivot crossing – will need to track cumulative percentages across multiple rounds until the 2% threshold is exhausted. Where one payroll covers staff in several joint committees, employers may be running capped and uncapped calculations side by side for many months.
The reform also remains politically contested. Trade unions and employer federations – in a rare unanimous position of the so-called Group of Ten – had proposed an alternative that would instead reduce the weight of energy prices in the index, and some coalition partners continue to push that option in budget talks. Employers should therefore expect further refinement through Royal Decrees and monitor developments closely.
Compliance here is less about a single decision and more about payroll mechanics. We recommend that companies employing staff in Belgium:
For international companies, this is precisely the kind of technical, fast-moving change that makes local expertise indispensable. Through its Employer of Record and payroll solutions in Belgium, Access Financial applies each joint committee’s indexation rules, the new cap and the associated NSSO contributions automatically, so your teams are paid correctly from day one. Contact us to review how the reform affects your Belgian payroll costs.
No. The reform does not abolish automatic wage indexation; it temporarily limits it for higher earners during two defined moderation periods, in 2026 and again from 2028. Sectoral collective agreements remain in force, salaries up to €4,000 gross per month continue to be indexed normally, and full indexation resumes once the 2% moderation effect has been achieved.
Employees affected by the €4,000 cap are those in the private or public sector, covered by Belgian social security, whose fixed monthly reference salary exceeds €4,000 gross. For part-time staff, the test is applied to the full-time-equivalent salary and pro-rated. Pensions and social benefits are subject to a separate, lower threshold of €2,000 gross per month.
Granting full indexation voluntarily is risky. The employer would pay the higher salary and still owe the new wage moderation contribution, and could additionally breach the Salary Moderation Act of 1996, exposing itself to administrative fines. Employers wishing to protect employees’ purchasing power should instead explore compliant alternatives, such as one-off bonuses or benefits, with proper legal advice.