Luxembourg Bonus & 13th Month Tax: How Much Will You Actually Keep?

The 13th month bonus is one of Luxembourg's most widely expected workplace benefits — most collective agreements include it, and many employees consider it a core part of their compensation. But the moment it hits your account, the excitement often fades: the tax deducted is usually higher than expected.

Here's why that happens, and how to calculate what you'll actually receive.

What Is the 13th Month Bonus?

The 13th month bonus is simply an additional month's salary paid once a year — typically in November or December, though some employers split it into June and December instalments. Despite its name, it is not legally required under Luxembourg's Labour Code, but it is included in most sectoral collective agreements (conventions collectives). Your employment contract will specify whether you're entitled to it.

Why Is the Tax So High?

The 13th month bonus is added to your total annual gross income and taxed as regular employment income. There is no special reduced rate for bonuses in Luxembourg — unlike some countries that apply a flat 10% or 15% rate on bonuses.

This means the bonus is taxed at your marginal rate — the rate applied to the top portion of your income. If your regular salary already puts you in a high bracket, your bonus gets taxed at that high marginal rate.

Example: €60,000 Base Salary + €5,000 Bonus

• Social contributions on the bonus ≈ €622
• Marginal income tax rate ≈ 32–34%
• Tax on the bonus ≈ €1,600–€1,700
• Solidarity surtax ≈ €112–€119
• Net bonus received: approximately €2,450–€2,600

So of a €5,000 bonus, roughly half goes to tax and contributions.

When Is It Paid?

Most Luxembourg employers pay the 13th month in November or December. Some pay 50% in June (summer) and 50% in December. A few employers include it in the monthly salary spread across the year — though this is less common.

Tips to Maximise Your Net Bonus

• Pension contributions: contributions to a 3rd-pillar pension plan (assurance-épargne pension) reduce your taxable income — useful to maximise in the same year as a large bonus
• Special expenses deduction: up to €3,200/year in qualifying premiums can be deducted
• Request timing: if you're close to retirement or planning a career break, timing when you receive a bonus can affect your annual tax bracket

Quickly Find Your Net Bonus

Every bonus situation is different — your tax class, base salary, and contribution ceiling all affect the result. Use our calculator to get an instant precise figure:

[👉 Use the Luxembourg Bonus Tax Calculator](/calculators/bonus-tax-calculator)

Input your gross salary and bonus amount, select your tax class, and see exactly what arrives in your bank account.