Requesting an NSSO certificate: who, where and how long it is valid
Step by step: which document you need for a withholding obligation check, where to request it and how long it stays valid.
When checking the withholding obligation, the question of a certificate comes up quickly. In practice three different documents are often confused. Here is which one you need, where to request it and how long it stays valid.
Three documents, three purposes
1. The online consultation with the NSSO. Not a paper certificate but an on-screen result showing whether your supplier has a contribution debt at that moment. For the withholding obligation this is the document that counts: it proves you checked on the day of payment.
2. The certificate limiting the withholding. Your supplier requests this from the FPS Finance when the actual tax debt is lower than the 15 per cent you would have to withhold. It states the exact amount and is valid for 20 days. If you pay within that period you may limit the withholding to that amount.
3. The NSSO certificate of contribution status. A company requests this about itself, for example for a public tender or a contractor authorisation. As a principal you do not need it for the withholding obligation.
Who requests what?
| Document | Requested by | Where | Validity |
|---|---|---|---|
| Contribution debt consultation | the principal or contractor making the payment | NSSO online application | the day of payment |
| Certificate limiting the withholding | the supplier | FPS Finance | 20 days |
| Certificate of contribution status | the company itself | NSSO | per tender, often 3 months |
The consultation step by step
- Collect the company number. Ten digits, printed on the invoice. The VAT number is the same number prefixed with BE. If you cannot find it, see how to find a supplier''s NSSO number.
- Run the consultation on the day of payment. A result from last week proves nothing for today''s payment.
- Run the tax check separately. The FPS Finance keeps its own list. A green light from the NSSO does not rule out a tax debt.
- Keep the dated result. For at least five years, together with proof of payment if you withheld.
What does it cost?
The NSSO consultation and the certificate limiting the withholding are free. The real cost is time: two lookups per supplier, repeated every payment round.
How long does it stay valid?
There is no validity of weeks or months for the consultation. It covers the payment it was made for. Only the certificate limiting the withholding has its own 20 day term.
Keeping proof automatically
Checkplicht runs the social security and tax consultation together, per supplier, at the frequency you set. Every result is stored as dated proof in pdf with a unique verification code. When something changes at a supplier, you get an email.
- The legal basis: article 30bis explained
- The obligation itself: withholding obligation
- Practical questions: frequently asked questions
Official sources
This page is informative and not legal advice.
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