Contractors Obligations and Liability

4works invoicing service/4works Oy is Reliable Partner member. Your customer can check our information on The Act on the Contractors Obligations and Liability and its implementation in the invoicing service. (Instructions from the ELY Center)

If you are a construction professional and you do construction work as a subcontractor or directly for the client, then the Act on the Contractors Obligations and Liability applies when the client requires you to submit documents in accordance with the Act.
As a self-employed person, when you invoice through a invoicing service, you are not employed by the invoicing service.

The invoicing service is affected by the Act on the Contractors Obligations and Liability in such a way that the invoicing service must be value added in the tax register and withholding tax register and that the invoicing service has a valid trade register extract.

The Act on the Contractors Obligations and Liability Section 5, Subsection 1. Sections 1-3 applies partly.
As a self-employed person, you must have your credit history in order and not have a tax debt, or at least have a payment agreement with the tax authorities.


In many construction sites, workers must have a photo ID and a tax number.
If you work in the construction industry and invoice your work through our invoicing service, you can also order a Valtti-card for yourself through us.

Valtti-Card - how to order

If you bill through our service and you want Valtti card for youself, log in to extranet and make an order on page MY INFORMATION, section Basic information and fill your tax number and attach a clear face image. Picture must be taken against a light background, picture must be similar to a passport photo.

Valtti card costs 50 euros, which will be charged from your salary.