Signal start revenue ratio

Stichting Inlichtingenbureau

When someone receives social assistance benefits, the municipality must check for new income that has not been reported. This income must be offset against the benefit. Instead of always investigating this itself, the municipality receives a single notification about this from Bureau InformatieDiensten Nederland (BIDN) at the start of this income.

Last change on 17th of July 2025, at 9:04 (CET) | Publication Standard 1.0

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

General information

Theme

Social Security

Begin date

Field not filled in.

Contact information

https://www.bidn.nl/over-ons

Link to publication website

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

Responsible use

Goal and impact

Bureau InformatieDiensten Nederland (BIDN) exchanges data every month between municipalities and the Polis administration of the Uitvoeringsinstituut Werknemersverzekeringen (UWV). This involves requesting data on wages, benefits and pensions. It then checks whether there are any new income ratios ('earnings'). If so, the municipality receives one notification of this.

Considerations

The 'Signal start Income Ratio' is part of the information service Samenloopsignalering (see algorithm 'Samenloopsignalering'). Only the points belonging to 'Signal start Income relationship' are discussed here

A person on benefits must self-report any changes that may affect the right to or amount of benefits. This applies, for example, to income from work, pension or other benefits. This income will then be offset. The municipality must check that a person on social assistance benefits has no new income that has not (yet) been reported. The Social Insurance Bank (SVB) must also check this for supplementary income provision for the elderly (AIO).

Instead of always doing their own research, municipalities can receive information from the Inlichtingenbureau when there is a new income. This allows them to engage with their residents when there is unknown income.

The algorithm ensures that a municipality only receives data from residents with social assistance benefits and a signal about new income. This protects citizens' privacy. 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

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

However, BIDN 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 generic basis of the processing of personal data in the context of the information service, see Samenloopsignalering.

A household is entitled to assistance when it has insufficient resources (income and assets) to meet its living costs. This principle is enshrined in the Participation Act. The signal start income relationship supports municipalities in checking whether social assistance recipients report this income, which is mandatory as described in Article 17 (Duty to Provide Information) in the Participation Act.

Basis for processing UWV and SVB (as sources)

- Sections 64(1)(b) and 68, Participation Act

- Sections 33(2)(a) to (c) and (9) j° Section 62 of the Work and Income Implementation Structure Act (SUWI Act)

- Section 35(2) and (4) j° Section 62 of the SUWI Act

Basis for processing SVB (as recipient)

- Article 47a, paragraph 1, Participation Act

Basis of processing BIDN

- Article 64, third paragraph, and Article 68, Participation Act

- Article 63, Article 5.24(1) and (3), SUWI Decree & Articles 6.2 and 6.6 SUWI Regulation

Basis of processing Municipalities:

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

- Article 62 SUWI Act

See also the Data Register BIDN. Processing activities Act SUWI / Participation Act on the BIDN website to be found via the following page: 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 benefit file of the municipality / SVB (A):

See the algorithm for concurrency signalling.

The demand file to UWV (B):

- Citizen service number

- Start date reference period, End date reference period

The response file to UWV (C):

- Input Citizen Service Number

- Date start period, end period

- LA Income relationship number

- LA Date start income relationship, end income relationship

- LA Payroll tax number

- LA Name of administrative unit

- Date start income period, end income period

- LA Code type of employment relationship, type of income relationship

- LA Date start income statement, end income statement

- LA Amount of wage SV, cash wage, value of non-cash wage,

- LA Number of hours worked

- LA Amount of social security contributions withheld, wage tax/national insurance contributions, wage tax/national insurance contributions withheld, holiday allowance, accrued holiday allowance entitlement, private use of car

- WGA Address roll code

- WGA Street name

- WGA House number

- WGA House number suffix

- WGA Houseboat reference

- WGA Houseboat reference

- WGA Postal code

- WGA City name

- WGA P.O. Box number

- WGA Street name abroad

- WGA House number abroad

- WGA Post code abroad

- WGA City name abroad

- WGA Region name abroad

- WGA Location name abroad

- WGA Country code ISO structured

- WGA PO Box number abroad

Signal to municipality/SVB (D):

- Lb number

- Name, address, postcode city of residence (employer)

- Start date of pay period

- End date of pay period Payroll obligation

- Wages on which wage tax is calculated

- Wage for the calculation of social insurance contributions

- The amount of the fixed value of the private use of a car

- The amount withheld for wage tax/ national insurance contributions

- The amount withheld as healthcare insurance contribution

- The amount taxed for wage tax/national insurance contributions, employment insurance contributions and healthcare insurance contributions

- The value of the wages that have not been paid in cash

- The amount accrued in holiday allowance.

- Name, address, postcode residence administrative unit.

- Start date gross benefit amount

- Start date gross payment amount

- End date gross payment amount

- Code nature of income

- Wages on which wage tax is calculated

- Wages for the calculation of social insurance contributions

- The amount of private use of a car

Technical design

Notes:

A. A municipality and SVB deliver a file relating to the current (social assistance) population to BIDN monthly via the secure client portal. After each delivery, a processing report is published, listing any errors in the delivery;

B. A (demand) file with which data are periodically requested in bulk from UWV regarding the benefit populations of municipalities / SVB;

C. The delivery of the bulk (response) file from UWV containing data from the Polis administration of the requested population;

D. (temporary) storage of supplied citizen service number (BSN) and associated signals in provision assistance population. BIDN compares whether there is overlap in the supplied data and applies logic to only forward new income ratios once to municipalities / SVB;

E. In case of overlap, BIDN issues a signal to municipalities / SVB.

External provider

Internally developed