NEN 4400 and SNA: why audited payroll matters when you hire in the Netherlands
When a Dutch hirer asks whether your payroll provider is NEN 4400 certified and SNA-registered, they are protecting themselves from chain liability for unpaid wage tax and social contributions. Here is what those marks actually mean.
What NEN 4400-1 certifies
NEN 4400-1 is the Dutch standard for the administrative integrity of staffing, payroll and EOR providers operating in the Netherlands. It covers identification of employees, correct contract administration, accurate payroll, timely wage tax and social-contribution payments, and compliance with the Wet Aanpak Schijnconstructies (WAS).
An independent audit firm conducts the certification audit and revisits twice a year. Failing an audit leads to suspension from the public SNA register - which clients can verify in real time.
What the SNA register adds
The Stichting Normering Arbeid maintains the public register of NEN 4400 certified providers. A hirer who books work through an SNA-registered provider is largely shielded from chain liability under the Inleneraansprakelijkheid rules - missing wage tax, missing VAT, missing pension contributions stay with the provider, not the client.
Many Dutch enterprise procurement processes will not contract with a non-SNA provider at all. For an international employer routing payroll through a partner, the SNA status of that partner is the single most useful compliance signal you can verify.
What an audited provider does differently
Document trail for every payroll run: identification, contract, working hours, tax credit application, pension contribution, payslip. Each item is auditable to the original source.
Monthly reconciliation between gross-to-net journals and Belastingdienst filings, with variance reports kept on file for the auditor.
Quarterly self-assessment under the SNA framework, fed into the audit firm's review window. The same dataset is what any procurement-driven supplier review will ask for, so the audit cycle doubles as a sales-enablement asset for the provider.
A G-account (geblokkeerde rekening) is offered as standard so hirers can deposit the wage-tax portion of an invoice directly with the Belastingdienst. That single mechanism removes the bulk of residual chain-liability risk for clients in regulated sectors.
Where ICS Payroll sits
Our own NEN 4400 audit is currently in progress; SNA registration is pending and expected in Q3 2026. Until our certification is published on the SNA register, chain-liability protected payroll is delivered through our SNA-registered EOR partner - so international employers hiring through that route already get a documented, audited and chain-liability-protected payroll by default.
We share a status update on our audit and our partner's SNA listing on request during procurement reviews. For enterprise hirers whose own compliance team needs to file the supplier into a vendor-risk register, that paperwork is ready in a day, not a quarter.
How to verify a provider in two minutes
Open the SNA register at normeringarbeid.nl and search the provider's legal name or KvK number. A current entry shows the certificate status and the auditing body. No entry means no chain-liability protection - regardless of what the website claims.
Cross-check the KvK number on the SNA listing against the entity that will actually issue the employment contracts. Group structures with multiple BVs sometimes hold the certification on a sister entity that is not the legal employer. If the names do not match, the protection does not transfer.
Ask for the most recent inspectierapport summary. Audited providers can produce it within a working day; providers that cannot are typically either not audited or recently suspended.