Knowledge base

Practical guides on the Belgian withholding obligation.

nsso·9/16/2026·7 min read

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.

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nsso·8/20/2026·7 min read

Checking social security debts: step by step

How to correctly check a contractor's social security and tax debts: what you need, how to read the result and what to do when an amount must be withheld.

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