13th Month Calculator 2026

What Is the 13th Month Salary?

The 13th month salary (dertiende maand in Dutch) is an additional payment equal to one month's gross salary, paid on top of the regular 12 monthly salary payments. It is essentially a year-end bonus that many Dutch employers provide, typically in December or early January. While it is called the “13th month,” it is effectively an 8.33% bonus on your annual salary (1/12 of 12 months).

For international workers moving to the Netherlands, the 13th month can be a significant -- and sometimes unexpected -- boost to total compensation. When combined with the legally required 8% holiday allowance (vakantiegeld), an employee with both benefits receives approximately 16.3% more than their quoted annual salary. On a base salary of €55,000, that means an extra €8,983 per year, bringing your total guaranteed cash compensation to approximately €63,983.

It is important to understand that the 13th month is not a legal requirement in the Netherlands. Unlike holiday allowance, which is mandated by law for all employees, the 13th month depends entirely on your employer's policies, your individual employment contract, or the collective labor agreement (CAO) that applies to your sector. This makes it a valuable negotiating point when evaluating job offers.

How Common Is the 13th Month in the Netherlands?

The 13th month is more common in the Netherlands than you might expect. Research indicates that approximately 30 to 40 percent of Dutch employees receive some form of 13th month payment. The prevalence varies significantly by sector:

In sectors covered by a CAO that includes a 13th month, the benefit is guaranteed for all employees within that agreement, regardless of individual negotiation. In sectors without a CAO or where the CAO does not include a 13th month, it may still be offered as a company-wide policy or negotiated individually.

13th Month vs. Holiday Allowance: Understanding the Difference

International workers often confuse the 13th month with holiday allowance because both represent extra payments beyond the regular salary. However, they are fundamentally different:

The key takeaway: holiday allowance is your legal right, while the 13th month is a bonus that depends on your specific employment arrangement. You can receive both simultaneously, and many employees in sectors like banking and government do.

How Is the 13th Month Taxed?

The 13th month is subject to income tax and national insurance premiums, just like your regular salary. However, because it is a one-time annual payment rather than part of your regular monthly salary, the tax treatment differs:

Your employer applies the special tax rate (bijzonder tarief) when processing the 13th month. This rate is determined by your estimated annual income and corresponds to your marginal tax bracket. The practical effect is that the tax rate on the 13th month is often higher than the rate you see on your regular monthly payslip:

Note: the actual special rate depends on your complete annual income including all bonuses and holiday allowance. These figures are illustrative approximations.

The high tax rate on the 13th month often disappoints employees who expect to receive a full extra month's net pay. If your regular monthly net is €3,200 on a €50,000 salary, you might expect €3,200 net from the 13th month. In reality, you receive closer to €2,600, because the 13th month pushes your annual income into higher bracket territory, and the special rate reflects that.

However, the total annual tax paid is correct and fair. The 13th month simply means your annual income is higher, so your overall effective tax rate is slightly higher too. If the special rate withheld too much, you would receive the difference back when filing your annual tax return.

Impact on Your Annual Income: A Complete Example

To illustrate the full impact of the 13th month on total compensation, let us walk through a comprehensive example:

Scenario: Marco is an Italian data scientist working in Rotterdam. His gross annual salary is €60,000, and his employer offers both the 13th month and the standard 8% holiday allowance.

• Base annual salary: €60,000 (12 monthly payments of €5,000)
• Holiday allowance (8%): €4,800 (paid in May)
• 13th month: €5,000 (paid in December)
• Total gross annual compensation: €69,800

Without the 13th month and holiday allowance, Marco's €60,000 salary would yield approximately €3,570 net per month. With both extras, his total annual net increases by approximately €5,800, averaging about €483 additional net per month over the year.

When Marco compares his Dutch offer with a position in Germany offering €65,000, he needs to consider that the Dutch €60,000 with 13th month and holiday allowance is actually €69,800 in total cash compensation -- making it significantly more competitive than it appears at first glance.

Negotiating the 13th Month as an Expat

For international workers, the 13th month represents a significant opportunity in salary negotiations. Here are practical strategies:

1. Ask about the CAO first. Before your negotiation, find out whether the company falls under a collective labor agreement that includes a 13th month. If it does, you will receive it automatically and do not need to negotiate it. You can find CAO information at UWV or ask the HR department directly.
2. Frame it as total compensation. If the employer does not offer a 13th month, calculate what the equivalent higher base salary would be. A €55,000 salary with a 13th month equals €59,583 total. You can negotiate either the 13th month directly or an equivalent salary increase.
3. Compare with your current package. If you are relocating from a country where year-end bonuses are standard (such as Spain, Italy, or many Asian countries), emphasize that the 13th month is a standard expectation in your current compensation and should be maintained.
4. Consider the mortgage implications. If you plan to buy a house in the Netherlands, having a 13th month documented in a CAO or employment contract strengthens your mortgage application. Banks view it as structural income, which can increase your maximum borrowing capacity by approximately 8%.
5. Look at the whole package. Some employers who do not offer a 13th month compensate with other benefits: higher pension contributions, stock options, performance bonuses, or additional vacation days. Evaluate the total package rather than focusing solely on the 13th month.

The 13th Month and Your Payslip

When the 13th month is paid, it typically appears as a separate line on your payslip (loonstrook) for that month. Here is what a December payslip might look like for an employee earning €50,000 with a 13th month:

Notice that the tax on the 13th month (€1,565) is proportionally higher than the tax on your regular salary (€1,000) because of the special rate application. This is normal and expected behavior.

Sectors with the Most Generous Year-End Benefits

Some sectors go beyond the standard 13th month and offer even more generous year-end benefits. Here is an overview of what top-paying sectors offer in terms of extra payments:

• Banking sector (CAO Banken): 13th month plus 8% holiday allowance, often supplemented by performance-based bonuses. Total extra payments can reach 20-25% of base salary.
• Government (CAO Rijksoverheid): Year-end allowance (eindejaarsuitkering) of 8.33% plus 8% holiday allowance. Some municipalities offer additional allowances.
• Energy sector: 13th month is standard in most energy company CAOs, plus holiday allowance, plus often a variable performance bonus.
• Pharmaceutical industry: Many companies offer 13th month through their CAO, and the sector generally pays above-average salaries.
• Large multinationals: Companies like Shell, Philips, ASML, and Unilever typically offer comprehensive packages that include a 13th month or equivalent bonus structure.

What Happens If You Leave Before December?

If your employment ends before the 13th month is normally paid, you are generally entitled to a proportional share. The calculation works as follows:

Example: You resign effective August 31, having worked from January 1 through August 31 (8 months). Your monthly gross is €4,500.

• Full 13th month: €4,500
• Pro-rated for 8 months: €4,500 × (8/12) = €3,000
• This amount is included in your final settlement along with accrued holiday allowance and unused vacation days.

However, the exact terms of pro-rating depend on your employment contract or CAO. Some agreements specify that the 13th month is only paid to employees who are still employed on a specific reference date (often December 1 or December 31). In that case, leaving before the reference date could mean forfeiting the entire bonus. Always check the specific terms in your contract or CAO before planning your departure date.

Tax Planning Around the 13th Month

Receiving the 13th month in December can have tax implications beyond the immediate withholding. Here are some considerations for tax-savvy expats:

• Annual tax return adjustments: If the special rate applied to your 13th month was too high (or too low), the difference is corrected in your annual tax return. This could result in a refund or additional payment.
• Income-dependent contributions: The 13th month increases your total annual income, which can affect income-dependent healthcare contributions (zorgtoeslag) and childcare subsidies (kinderopvangtoeslag). If you receive these benefits, the additional income from the 13th month may reduce your entitlements.
• Box 3 reference date: The 13th month paid in December increases your bank balance on January 1, which is the reference date for Box 3 wealth tax. If your total assets are close to the threshold (€57,000 per person in 2026), the timing of the payment could push you above it.
• Mortgage interest deduction: If you have a Dutch mortgage, the extra income from the 13th month does not reduce your mortgage interest deduction. The deduction is based on the interest paid, not on your income level (though the tax benefit percentage does depend on your bracket).

Frequently Asked Questions

Sources and Further Reading

The information on this page is based on:

• Belastingdienst: Payroll tax tables and special rates
• Rijksoverheid: Employment conditions and collective labor agreements
• CBS: Employment statistics and compensation data

The 13th month terms depend on your specific employment contract or collective labor agreement. Always consult your HR department or the relevant CAO document for details specific to your situation.