Reading and understanding your payslip: all codes explained

You open your payslip and see a long list of codes, percentages and amounts. Gross salary, NSSO contribution, professional withholding tax, special social security contribution. And then there are abbreviations no one ever explained to you.

Sound familiar?

You're not alone. Most employees in Belgium admit they don't fully understand their payslip. And honestly? Even employers sometimes struggle with it. It isn't simple either. Between your gross salary and what actually lands in your account lies a whole journey of deductions, contributions and calculations.

In this article, we walk you through your payslip step by step. Every line, every amount, every code. So that from now on you know exactly where your money goes, and whether your payslip is correct.

What exactly is a payslip?

A payslip (also called a pay slip or wage statement) is the document your employer is legally required to give you with every salary payment. It shows how your salary was calculated and which deductions were made.

Under Belgian law, every employer must provide a pay statement so the employee can check exactly how their salary was calculated. The FPS Employment, Labour and Social Dialogue sets out the minimum details it must contain.

What must always appear on your payslip?

• Your name and personnel number
• The pay period (for example, 1 to 31 January 2026)
• Your gross salary
• All deductions listed separately (NSSO, professional withholding tax, any other deductions)
• Your net salary
• The meaning of all codes and abbreviations used

That last point matters. If your employer or social secretariat uses abbreviations, they have to be explained somewhere. You'll usually find that explanation on the individual account or in an appendix.

From gross to net: how your payslip works

Here's the key point: the journey from your gross salary to your net salary happens in a few clear steps. Once you grasp these, you understand most of your payslip.

Step 1: the gross salary

Your gross salary is the starting point. It's the salary you contractually agreed with your employer, before social security contributions and taxes are deducted.

On your payslip, the gross salary is usually broken down into:

• Basic salary: your fixed monthly salary, or your hourly rate multiplied by the hours worked
• Bonuses and allowances: overtime, weekend work, night work, shift premiums
• Guaranteed salary during illness: if you were ill but are entitled to continued payment
• Public holiday pay: payment for statutory public holidays
• Other salary components: seniority premiums, function premiums

All these elements together make up your gross monthly salary. So that figure isn't what you receive. It's where the calculation starts.

Want to know exactly how the gross-to-net calculation works? Read our article on gross-to-net calculation for the full formula.

Step 2: the 13.07% employee NSSO contribution

This is where it gets legal. Not boring-legal, but important.

13.07% of your gross salary is deducted as your personal NSSO contribution. NSSO stands for the National Social Security Office (Rijksdienst voor Sociale Zekerheid). This contribution funds the entire Belgian social security system: your pension, health insurance, unemployment benefits and child benefit.

Worked example: Say your gross salary is 3,000 euros. You then pay 3,000 x 13.07% = 392.10 euros in NSSO contributions.

There's an important difference between blue-collar and white-collar workers. For blue-collar workers, the NSSO contribution is calculated on 108% of the gross salary. That sounds strange, but it's a historical leftover. In the past, blue-collar workers didn't receive holiday pay through their employer but through the National Annual Holidays Office, and that extra 8% compensated for it.

In practice, this means a blue-collar worker with the same gross salary pays slightly more in NSSO contributions than a white-collar worker. The gap is gradually shrinking thanks to the single status, but in 2026 it still exists.

Want to know more about NSSO contributions and exactly how they're calculated? Check our guide on calculating NSSO contributions.

Step 3: the taxable salary

After the NSSO contribution is deducted, you're left with your taxable salary. This amount is the basis for the next step: the professional withholding tax.

Worked example (continuing ours): Gross salary: 3,000 euros Minus NSSO contribution: -392.10 euros Taxable salary: 2,607.90 euros

On your payslip, this amount is sometimes labelled 'belastbaar' (taxable) or 'imposable'.

Step 4: the professional withholding tax

The professional withholding tax is essentially an advance on your personal income tax. Instead of receiving one big tax bill once a year, your employer withholds part of your salary each month and pays it to the tax authorities.

How much professional withholding tax you pay depends on several factors:

• Your taxable salary (the higher it is, the more you pay)
• Your family situation (single, cohabiting, married)
• The number of dependent children
• Whether your partner has a professional income
• Any other reductions

Belgium uses progressive tax brackets. That means you don't pay the same percentage on your entire income. The first bracket is taxed at a lower rate than the higher ones. For 2026, the brackets are as follows (indicative):

• 0 to 15,820 euros: 25%
• 15,820 to 27,920 euros: 40%
• 27,920 to 48,320 euros: 45%
• Above 48,320 euros: 50%

Note: these brackets apply on an annual basis. The professional withholding tax on your monthly salary is a monthly translation of them, taking your personal situation into account.

Since 2026, the withholding tax tables have been adjusted so that the deduction lines up better with the final income tax. This should mean you less often see a big gap between what was withheld and what you have to pay in, or get back, at your tax return.

Step 5: the special social security contribution

On top of the ordinary NSSO contribution, you also pay a special social security contribution. This is an extra deduction that depends on your household income.

For a single person with a gross monthly salary of around 3,000 euros, this contribution comes to roughly 30 to 50 euros a month (indicative). The exact amount varies according to your total household income.

On your payslip, this often appears as 'Bijz. bijdrage SZ' or a similar abbreviation.

Step 6: your net salary

After all these deductions, you're left with your net salary. That's the amount actually paid into your account.

Full worked example:

• Gross salary: 3,000.00 euros
• Employee NSSO contribution (13.07%): -392.10 euros
• Taxable salary: 2,607.90 euros
• Professional withholding tax (indicative): -475.00 euros
• Special social security contribution (indicative): -40.00 euros
• Net salary: approximately 2,092.90 euros

This is, of course, a simplified example. In practice, other factors come into play, such as the work bonus, benefits in kind, or net allowances. But the broad strokes are always the same.

Common codes on your payslip

Every payslip uses codes and abbreviations, and they differ from one social secretariat to another. Securex uses different codes than SD Worx, Acerta or Partena. Even so, certain elements come back everywhere.

Salary codes you'll see everywhere

Basic salary and hours worked:

• Days/hours worked: the number of days or hours you actually worked
• Public holidays: paid statutory public holidays falling within the pay period
• Guaranteed salary during illness: your salary during the first days of illness (paid by the employer)
• Klein verlet (short leave): paid absence for family events (marriage, death, birth)
• ADV days: working-time reduction days, extra days off if your sector provides for them

Bonuses and allowances:

• Overtime: hours above normal working time, often with a premium of 50% or 100%
• Night premium: a supplement for night work
• Weekend allowance: extra pay for work on Saturday or Sunday
• Seniority premium: extra pay based on your years of service
• End-of-year bonus: the thirteenth month or end-of-year allowance (usually appears in December)

Deductions:

• RSZ WN: your personal NSSO contribution as an employee
• BV or Bedrijfsvoorh.: the professional withholding tax
• Bijz. bijdrage SZ: the special social security contribution
• Work bonus: a reduction of your NSSO contribution if your salary is below a certain ceiling
• Net deduction: sometimes you'll see deductions for meal vouchers, group insurance or other items

In our experience with thousands of payroll calculations a month, we see that employees stumble most over the codes for bonuses and allowances. These are coded differently by each social secretariat, so you sometimes end up comparing apples to oranges when you change employer.

How to find what your specific codes mean

Every social secretariat is required to make the meaning of the codes it uses available. You'll usually find it:

• On the individual account (the yearly overview of all your salary data)
• In a separate document your employer gave you when you started
• On your social secretariat's online portal (for example MySecurex, MyAcerta, or SD Worx Employee Self Service)

Can't find it? Ask your employer or HR department. They're legally required to give you that information.

Benefits in kind on your payslip

A company car, a work smartphone, a laptop you can also use at home. Sounds nice. But on your payslip these appear as 'benefits in kind' (or BIK), and that has an impact on your net salary.

A benefit in kind is any advantage your employer grants you outside your normal salary that you're also allowed to use privately. The tax authorities regard it as part of your income, so you pay tax on it.

How does it work on your payslip?

The benefit in kind is added to your gross salary for the calculation of the professional withholding tax, then subtracted again afterwards. After all, you don't receive it in cash. The result: you pay more professional withholding tax, but your net salary drops by that extra amount of withholding tax.

Common benefits in kind and their flat-rate values (indicative, 2026):

• Company car: the value depends on the catalogue value, CO2 emissions and age of the vehicle. The formula is complex and is indexed every year
• Private use of a smartphone/tablet: a flat rate of 36 euros a year for a smartphone, 36 euros for a tablet
• Private use of a PC/laptop: a flat rate of 72 euros a year
• Free housing: a flat-rate value based on the cadastral income
• Free heating and electricity: fixed annual flat rates, indexed

You'll usually see the benefit in kind on your payslip as a separate line, both under 'additions' and under 'deductions'. The balance is zero in your net salary, but the extra professional withholding tax you pay is real.

Employer contributions: what you don't see

This is where it gets interesting, especially if you're an employer or want to understand your total labour cost. On top of the gross salary shown on your payslip, your employer also pays employer contributions to the NSSO. They don't appear on your payslip, but they very much exist.

The basic employer contribution is around 25% of the gross salary (after the tax-shift reduction). On top of that come sector-specific contributions that vary by joint committee. In some sectors, total employer contributions run to 30% or more.

Say you earn 3,000 euros gross. Your employer then pays around 750 to 900 euros on top in employer NSSO contributions. Plus your gross salary, plus any extra-legal benefits. So the total labour cost for your employer is a good deal higher than what you see on your payslip.

Want to know what an employee really costs? Read our article on calculating labour cost for the full picture.

After more than 15 years in Belgian payroll, we see that many employers are shocked when they first see the full labour cost. The difference between the employee's net salary and the total cost for the employer is exceptionally large in Belgium. That's not an opinion, that's a fact.

Holiday pay on your payslip

Holiday pay is one of the most confusing elements on the payslip, because the system differs for white-collar and blue-collar workers.

White-collar workers

As a white-collar worker, you receive two kinds of holiday pay.

Single holiday pay: this is simply your normal salary during your holiday days. You don't work, but you're paid all the same. It appears on your regular monthly payslip.

Double holiday pay: this is an extra payment, calculated as 92% of your gross monthly salary. Most employers pay it out in May or June. On your payslip you'll see it as a separate line, with its own NSSO calculation.

Note: a specific deduction rate applies to double holiday pay. The professional withholding tax on double holiday pay is a fixed percentage (indicatively 17.16% for the first bracket), not the usual progressive rate.

Blue-collar workers

Blue-collar workers don't receive their holiday pay through their employer but through the National Annual Holidays Office (RJV) or a holiday fund. So that amount doesn't appear on your regular payslip. You receive a separate document for it.

Want to know more about the calculation? Check our article on calculating holiday pay.

The work bonus: when your salary is lower

If your gross monthly salary is below a certain ceiling (indicatively around 3,100 euros gross in 2026), you're entitled to a work bonus. This is a reduction of your personal NSSO contribution.

On your payslip you'll see this as a negative amount under the NSSO deductions. The effect: your net salary goes up, even though your gross salary stays the same.

The work bonus was introduced to make working more financially attractive than not working. The lower your salary, the higher the work bonus. Above the ceiling, the bonus disappears.

Net allowances and expense reimbursements

Some amounts on your payslip are net amounts. That means no NSSO contributions or taxes are deducted from them. These appear at the bottom of your payslip, separate from the gross-to-net calculation.

Common net allowances:

• Meal vouchers: your employer's share is exempt; your own share (max. 1.09 euros per voucher) is deducted from your net salary. More on this in our article on meal vouchers for employers
• Commuting: part of your travel costs is reimbursed net
• Homeworking allowance: a flat-rate allowance for those who work from home structurally (indicatively up to 154.74 euros a month in 2026)
• Expense reimbursements: reimbursement of professional costs based on supporting documents

These amounts are added to your net salary after the entire gross-to-net calculation.

How to check your payslip is correct

Let's take a step back. You now understand how your payslip is put together. But how do you know the calculation is correct?

A few checks you can do yourself:

Check your gross salary. Does it match what's in your contract? Have you had an indexation that should be reflected? Is the number of hours or days correct?

Check the NSSO contribution. Take your gross salary and multiply it by 13.07%. Does that amount match what's on your payslip? (For blue-collar workers: first multiply by 108%, then by 13.07%.)

Look at your family situation. The professional withholding tax depends on your household situation and the number of dependent children. If there's an error there, you pay too much or too little withholding tax.

Count the days worked. Do the days worked match your own count? Are sick days, holidays and public holidays listed correctly?

Something wrong? Report it to your employer or HR department as soon as possible. Errors on payslips do happen, even at reputable social secretariats. The sooner you flag it, the easier it is to correct.

You can check all this manually, or you can hand your payroll administration to a partner like Recruit. Your salary calculations are then run automatically according to current legislation and the correct joint committee. Errors from manual entry become a thing of the past.

Payslips differ by joint committee: here's why

The rules can differ by joint committee and sector. That's one of the reasons payslips can look so different from one company to the next.

Every joint committee (abbreviated JC) has its own agreements on:

• Salary scales and minimum wages
• Bonuses and allowances (end-of-year bonus, eco-vouchers, seniority premium)
• Working time and ADV days
• Travel costs and other allowances

So in JC 200 (white-collar workers) you get different bonuses than in JC 302 (hospitality) or JC 124 (construction). The codes on your payslip reflect those sector-specific agreements.

At Recruit, we work with every Belgian joint committee on a daily basis. We regularly see employers apply the wrong salary scale or forget a sector-specific premium. That can lead to wage arrears and even penalties during a social inspection.

In short

Reading your payslip isn't higher maths, but you do need to know what you're looking at. The journey from gross to net runs through the NSSO contribution (13.07%), the professional withholding tax (progressive, depending on your situation) and the special social security contribution. On top of that come benefits in kind, holiday pay, the work bonus and net allowances that complete the picture.

The most important thing? Check regularly that the basic data on your payslip is correct. Your gross salary, your family situation, the number of days worked. If that base is right, the calculations that follow it usually are too.

And as an employer? You now know that the payslip explanation your employees need goes further than 'just look at the net salary at the bottom'. Transparency about the salary calculation builds trust. And that starts with a correct, clear payslip.

Frequently asked questions

Is my employer required to give me a payslip? Yes. Under Belgian labour law, your employer must provide a pay statement with every salary payment. It must clearly show how your salary was calculated and which deductions apply. The meaning of the codes used must also be available.

Why does my net salary change every month? There can be various reasons. The number of working days differs from month to month, you may have worked overtime or had sick days, or an indexation was applied. Changes in your family situation (a dependent child, marriage) also affect the professional withholding tax.

What if there's an error on my payslip? Report it to your employer or HR department as soon as possible. They can have the correction made at the social secretariat. If the error isn't fixed, you can contact the social inspectorate or your trade union.

What's the difference between gross salary and taxable salary? Your gross salary is your salary before all deductions. Your taxable salary is your gross salary minus the NSSO contribution (13.07%). The professional withholding tax is calculated on that taxable salary.

Do I pay NSSO on my holiday pay? Yes, an NSSO contribution is deducted on double holiday pay. The professional withholding tax on double holiday pay is different from that on your regular salary, though: a separate, often lower rate applies.

---

How Recruit helps you with this

Not keen to puzzle over NSSO percentages and salary calculations yourself? We get it.

With Recruit:

• Contracts in under 60 seconds: create trial and temp contracts without hassle
• Automatic salary calculation: correct pay according to current legislation and your joint committee
• Dimona (immediate employment declaration) and social documents: we handle all declarations, you focus on your business
• 24/7 personal support: always a dedicated contact who knows your company
• No fixed monthly costs: pay only for what you use

Try Recruit or get in touch with our HR experts for tailored advice.

---

The information in this article is purely informative and does not replace professional legal or accounting advice. Labour legislation changes regularly. Always consult the current legislation or contact an HR expert for advice tailored to your situation. Please note: the rules can differ by joint committee and sector. This article provides general guidelines. For specific advice tailored to your sector, contact our HR specialists.