As your employer, JobService will deduct a percentage of your salary for income tax and national insurance contributions.
You can have a right to income tax and social insurance contributions credit. You can find more information on the site www.belastingdienst.nl.
This credit may only be used at one employer or benefits agency. You will indicate through HR2day whether JobService should apply the income tax and social insurance contribution credit to your earnings. It is most advantageous for you to have the income tax and social insurance contribution credit applied by the employer/benefits agency where you earn the highest monthly gross sum.