Signal revenue Box 1

Stichting Inlichtingenbureau

Income can affect the right and amount of a benefit. Stichting Inlichtingenbureau (IB)* uses an algorithm to determine, based on data from the Tax Office and municipalities, whether there is income (box 1) during the period when an assistance benefit was also received.

Last change on 5th of August 2025, at 12:41 (CET) | Publication Standard 1.0

• Publication category: Impactful algorithms
• Impact assessment: DPIA
• Status: In use

General information

Theme

Social Security

Begin date

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Contact information

* De officiële, statutaire naamswijziging van Stichting Inlichtingenbureau naar Bureau InformatieDiensten Nederland (BIDN) volgt op een later moment. Tot die tijd gebruiken we in officiële documentatie de naam Stichting Inlichtingenbureau (IB). https://www.bidn.nl/over-ons

Link to publication website

https://www.bidn.nl/rechtmatigheid-samenloopsignalering

Responsible use

Goal and impact

Through the IB, municipalities receive information on box 1 income of residents on social assistance benefits. Municipalities can use this to check whether someone is rightly receiving a benefit and whether the amount of the benefit is correct.

This is done in addition to the signals 'Start Income Relationship' and 'Support Income Settlement Assistance'. Thus, municipalities receive information if someone has income while receiving social assistance benefits. Box 1 income is, for example, income from self-employment, alimony or income from work such as freelancing, childcare or a newspaper round.

Based on the tax return, it shows whether a person had box 1 income while on welfare. This information helps municipalities find income that is not visible in UWV's data. Thus, they do not have to rely solely on the information provided by citizens themselves.

Considerations

The 'Signal Income Box 1' is part of the information service Samenloopsignalering. (see algorithm 'Samenloopsignalering'). Only the specific points about 'Signal Income Box 1' are explained here.

Income can affect the right and amount of a benefit. The IB uses data from the Tax and Customs Administration to check whether income and benefit are combined, in order to check whether the benefit is justified and correct.

By 'concurrence' we mean that a current benefit coincides with the tax year in which the box 1 income was received. The Box 1 indication is about the types of income that were there in that year.

Information from the income tax return may not be known until later in the year. Or it may sometimes be adjusted during the year. Because this information can affect the right or amount of a benefit, a monthly check is made to see if there are any changes in this data. This way, any changes can be detected quickly.

The algorithm ensures that the municipality only receives the data of residents on welfare benefits who have income in Box 1. With this, we protect the privacy of citizens. An advantage of this algorithm is that it works much faster than when someone does it by hand. This saves a lot of time for municipal employees. Also, fewer mistakes are made this way.

Human intervention

For the IB itself, this algorithm does not involve human intervention. The algorithm executes rules devised by humans and is not 'self-learning'.

However, the IB does ensure that the processing process has been done properly.

The municipality decides whether and how to deal with a change.

Risk management

Citizen privacy is a major concern. That is why we periodically check whether there are risks and what can be done about them. This is called privacy impact assessment (PIA).

Legal basis

For the general basis of processing personal data in the context of the information service "Samenloopsignalering", see the algorithm "Samenloopsignalering".

Basis of processing Tax Authorities:

- Sections 64(1)(c) and 68 of the Participation Act

- Section 45(1)(c) Income Support for Older and Partially Disabled Former Self-Employed Persons Act (IOAW)

- Section 45(1)(c) Income Support for Older Workers Act (IOAZ).

Basis for processing IB:

- Sections 64(3) and 68 of the Participation Act

- Article 45(2), IOAW

- Article 45(2), IOAZ

- Section 63 Work and Income Implementation Organisation (SUWI) Act, Section 5.24(1) and (3), SUWI Decree & Sections 6.2 and 6.6 SUWI Regulation

Basis of processing Municipalities:

- Chapter 5 'Implementation' and Chapter 6 'Powers and facilities municipalities' Participation Act

Assistance is granted if the applicant has insufficient means (income and assets) to meet the costs of living (Participation Act articles 31, 32 and 33). To establish this, social services and the SVB test the applicant's available resources.

See also the Data Register. Processing activities Act SUWI / Participation Act on the IB website at: https://www.bidn.nl/privacy-beleid

Links to legal bases

Participatiewet: https://wetten.overheid.nl

Link to Processing Index

https://www.bidn.nl/privacy-beleid

Impact assessment

Data Protection Impact Assessment (DPIA): https://www.bidn.nl/privacy-beleid

Operations

Data

The municipality's benefit file (A):

See the concurrency algorithm.

The demand file to the tax authorities (B):

- BSN

- Tax year

- Municipality code

The response file to the tax authority (C):

- BSN

- Commune code

- Box1 Tax year

- Taxable profit (final items), Box1 self-employed, indication indicating self-employment income (Y/N)

- Box1-alimony, indication indicating spousal maintenance income (Y/N)

- Box1-row, indication indicating income from other work (Y/N)

- Tax partnership (Y/N)

- Described (Y/N

- Declarant's share of basis (Y/N)

Signal to municipality (D):

See the algorithm "Concurrence" for the data that are by default part of a signal.

Below the data specifically belonging to this signal

- Box1 Tax year

- Box1 self-employed, indication of self-employed income

- Box1-alimony, indication of income from partner alimony

- Box1-row, indication of income from other activities

Technical design

A. A municipality delivers a file relating to the current social assistance population to the IB monthly via the secure client portal. After each delivery, a processing report is published, listing any errors in the delivery;

B. A (demand) file that is used to periodically (monthly) request data in bulk from the Tax and Customs Administration regarding the municipal / SVB benefit populations (NB. Once a year in mid-June an update is issued from the Tax and Customs Administration for the most recent tax year, based on the processing of tax returns);

C. The delivery of the bulk (response) file from the Tax and Customs Administration containing data relating to Box 1 of the extracted population;

D. (temporary) storage of supplied BSN and associated signals in provision assistance population. The IB uses an algorithm to compare whether (Box 1) income was received in the year in which the benefit was also active;

E. In case of overlap with the benefit period, the IB makes a signal available to the municipality (and/or SVB). Depending on the reporting requirements set by municipality, a concurrence signal report is published on the portal.

External provider

Internally developed