EUROCERTIF
In the construction sector, administrative diligence is not a mere formality: it determines the very right to work for certain clients, access to public tenders, and sometimes the survival of the company. Being in order with the NSSO (social security) and with VAT is now closely scrutinised, both by the authorities and by clients.
For a contractor, understanding these obligations — and above all being able to prove them quickly — has become a real competitive advantage. Here is an overview of what you need to master.
ONSS et TVA : de quoi parle-t-on ?
The NSSO, the National Social Security Office, collects social contributions on wages. Every construction employer must declare its workers and pay these contributions on time. VAT, for its part, is the tax the company collects on its invoices and remits to the State, after deducting the VAT paid on its purchases.
These two flows represent large and regular amounts. A delay or a payment default quickly translates into a debt that can build up and trigger control mechanisms specific to the construction sector.
La responsabilité solidaire, comment ça marche ?
When a company uses a subcontractor for real-estate works, it is required to check that this subcontractor has no social or tax debts. This mechanism, called joint liability, protects the State against companies that accumulate unpaid amounts.
If the subcontractor has a debt, the client becomes jointly liable for it — and may therefore have to pay it on the subcontractor’s behalf. This is a very concrete reason why professional clients look closely at the situation of their partners before signing.
Concretely, a general contractor who subcontracts the roofing to a company that owes money to the NSSO could be asked to pay that debt. Hence the importance, for the subcontractor, of being beyond reproach on this point.
The withholding obligation on invoices
Lorsqu’une dette ONSS ou fiscale existe au moment du paiement, le donneur d’ordre doit effectuer une retenue sur le montant de la facture et la verser directement à l’administration. Cette retenue est en principe de 35 % pour les dettes sociales et de 15 % pour les dettes fiscales.
Failing to apply this withholding exposes the client to having to pay the debt itself, sometimes increased as a penalty. Conversely, a contractor with no debt allows its clients to pay it in full and immediately, with no complication or risk.
The certificates to know
To prove its good standing, the company has official certificates, which it is best to always have on hand.
- The NSSO certificate of no debt, which confirms the absence of social-contribution arrears.
- The tax certificate, which attests to the absence of VAT and tax debts.
- These documents can be viewed and downloaded through the authorities’ online services.
Having these certificates up to date and ready to share is a winning reflex: it immediately reassures a hesitant client and speeds up signing.
The consequences of an unsettled debt
Letting an NSSO or VAT debt take hold is not just an accounting issue. The consequences can be severe:
- Automatic withholdings on your invoices, which drain your cash flow.
- Exclusion from public tenders, which require a sound social and tax situation.
- A loss of confidence among private clients, who prefer to avoid the risk of joint liability.
- In serious cases, prosecution and, ultimately, a real risk of bankruptcy.
Construction and public tenders
For companies targeting public tenders, social and tax compliance is non-negotiable: it is a condition of access. A debt, even a modest one, can be enough to rule out a bid, regardless of its technical quality or price. Keeping your accounts up to date therefore also keeps the doors to public projects open.
How to stay compliant
- File and pay your VAT returns on time, monthly or quarterly depending on the scheme.
- Pay NSSO contributions regularly and avoid building up the slightest arrears.
- Anticipate your cash flow so you are not short when due dates arrive.
- In case of difficulty, quickly request a repayment plan rather than letting the debt grow.
- Keep your certificates of no debt up to date, ready to be provided to any client.
This is precisely one of the three requirements of a EuroCertif certification: the absence of any debt to the State (NSSO, VAT, withholding tax). A certified company has therefore already demonstrated that it is in order on this essential point — and proves it to its clients at a glance, thanks to a verifiable label.