Ex officio healthcare insurance refund (seafarer)

Dutch Tax and Customs Administration

This page contains information about the algorithm 'Ex officio refund of Healthcare Insurance Act (seafarer)'. This algorithm retrieves the tax wage data for calculating the refund of the income-related Healthcare Insurance Act contribution on seafarers' wages.

Last change on 30th of October 2025, at 15:46 (CET) | Publication Standard 1.0

• Publication category: Impactful algorithms
• Impact assessment: Field not filled in.
• Status: In use

General information

Theme

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Begin date

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Contact information

[e-mail]

Link to publication website

https://over-ons.belastingdienst.nl/onderwerpen/omgaan-met-gegevens/algoritmeregister/

Link to source registration

https://over-ons.belastingdienst.nl/onderwerpen/omgaan-met-gegevens/algoritmeregister/ambtshalve-teruggaaf-zorgverzekeringswet-zeevarende/

Responsible use

Goal and impact

The Tax Authority checks withholding agents for correct and complete declaration and payment of payroll taxes. Payroll taxes consist of wage tax, national insurance contributions, employee insurance contributions and the income-related Healthcare Insurance Act contribution. Withholding agents (such as an employer, pension fund or benefits agency) deduct the wage tax and national insurance contributions from their employee's wages and, in some cases, the income-related Healthcare Insurance Act contribution. They remit this to the Tax Office. The employee insurance contributions and usually the income-dependent Healthcare Insurance Act contribution are not deducted from the employee's wage, but are paid by the employer to the Tax Administration.

A seafarer is a person working on a seagoing vessel. This group is subject to a zero rate for the Health Insurance Act under certain conditions. Sometimes the withholding agent wrongly deducts the income-related Healthcare Insurance Act contribution on seafarers' wages. The Tax Administration spontaneously returns this wrongly remitted income-related Healthcare Insurance Act contribution to the withholding agent.

The purpose of the algorithm is to select the tax wage data of persons known to the Tax Administration as seafarers for a correct refund of the Healthcare Insurance Act contribution.

Considerations

The algorithm Ex officio refund of Health Insurance Act (seafarer) is important for a correct refund of income-dependent health insurance contributions. We want to do this carefully. The algorithm can support a Tax Administration employee in this. As a result, the assessment is more careful, efficient and uniform.

Human intervention

Human intervention in the Tax Administration context implies that a competent and knowledgeable employee plays a substantial role in decision-making.

The operation of the algorithm always involves human intervention. The algorithm detects and selects. It is the Tax Administration employee who makes the decision.

Risk management

The General Administrative Law Act (Awb) requires the government's actions to be transparent and lawful. The Tax Administration observes the general principles of good governance when applying and developing algorithms.

The algorithm uses data collected under various tax laws. As required by the AVG, no more data is used than necessary.

The selection rules are reviewed periodically and adjusted if necessary to remain compliant with laws and regulations.

Legal basis

1. General Administrative Law Act:
2. General Data Protection Regulation:
3. Archives Act 1995:
4. General Administrative Law Act:
5. General State Tax Act:
6. Seafarers Regulations
7. General Data Protection Regulation (Implementation) Act
8. Health Insurance Act

Links to legal bases

• General Administrative Law Act:: https://wetten.overheid.nl/BWBR0005537/
• General Data Protection Regulation:: https://eur-lex.europa.eu/legal-content/NL/TXT/HTML/?uri=CELEX:32016R0679
• Archives Act 1995:: https://wetten.overheid.nl/BWBR0007376/
• General Administrative Law Act:: https://wetten.overheid.nl/BWBR0005537/
• General State Tax Act:: https://wetten.overheid.nl/BWBR0002320/
• Seafarers' regulation: https://wetten.overheid.nl/BWBR0032140/
• General Data Protection Regulation Implementation Act: https://wetten.overheid.nl/BWBR0040940/
• Health Insurance Act: https://wetten.overheid.nl/BWBR0018450/

Elaboration on impact assessments

• Privacy and AVG

The use of data is tested against the General Data Protection Regulation (AVG). Reviewing personal data reveals any privacy risks and allows appropriate measures to be taken.

The AVG prescribes that no more data should be used than necessary. This is called data minimisation. The Tax Administration regularly examines whether the data used are still necessary and may therefore be used.

• Use of special personal data

The algorithm does not use special personal data.

• Equality and non-discrimination

The algorithm is assessed in line with applicable non-discrimination principles for direct and indirect discrimination. Processing as little personal data as possible reduces the risk of direct discrimination. Employees involved in developing and managing the algorithms receive training on data protection and bias.

Operations

Data

1. Personal data taxpayer (BSN, date of birth)
2. Tax wage data
3. Zvw data

Links to data sources

• Personal data taxpayer (BSN, date of birth): Basisregistratie Personen (BRP)
• Tax payroll data: Belastingdienst
• Zvw data: Belastingdienst

Technical design

The algorithm consists of selection rules drawn up by content experts based on laws, regulations and expertise.

Seafarers are treated separately. This algorithm retrieves the data needed by a handler to process the file. The algorithm does not make decisions.

The algorithm is not self-learning. This means that the algorithm does not develop itself during its use.

External provider

The algorithm was developed by staff at the Inland Revenue and is also maintained internally.