This was sent in by email by a registered artisan on this site who is employing other artisans and who asked not be identified because of possible reprisals from those working "on the black" :-

"This little fact applies to any person who employs clandestine workers, registered artisans working outside their remit (eg a gardener replacing a roof) and uninsured registered or non registered trades.

1) If an accident occurs where someone is injured or even killed in the process of work then the ‘employer’ who is legally the house owner is liable for all costs. For example, you pay someone ‘au noir’ to do your building work. He has an accident and is hospitalised. Under French law as he is not registered, you are liable as his employer to pay: all medical costs, his social security charges, the social security charges you should be paying as his employer, the wages he should have been able to earn all the time he is off sick and the worker can then take you to court for damages or his family if the artisan is killed. The ‘employer’ will fine an investigation by the Inspecteur du Travail, URSAFF and any other official body that sees fit, and will be liable for paying fines and chares associated with employing clandestine labour, avoiding social charges and tax. The same will be applied to artisans who are working outside there registration as you have asked them to do the work and legally you become there ‘employer’. Again if an registered artisan is working uninsured but within the remit of his registration, the house owner can become liable for any medical costs etc should the artisan be injured. Injuries at work are not covered by an artisans top up insurance and they can make a claim against the employer or the artisans insurance if they feel the need.

2) The INSEE who hold all the registrations of Artisans only ever show the main trade of that person and though you can check the Siret Numbers out, it is always safer to physically see the registration card or KBIS of the artisan, plus a COPY of their insurance. The reason for this is that as many legitimate artisans have found the INSEE do not record everything they are registered for, however ALL that information is found on the KBIS, and the green Artisan card that legally has to be carried. Insurance companies in France underwriting artisans always do more checks than the Chambre de Metiers. They do not rely solely on four recommendations from previous clients as these can and have been fraudulently created so that people can register as an artisan in France.

3) If you have any concerns about an artisan, take their name, full address and land line number (not a mobile as many cowboys work this way), plus if they have it, details of their Siret number. You put any of these details in to: http://www.cofacerating.fr/ Otherwise known as LesEchos.fr. If you get no results from any of the information you put in then you need to assume that the person is NOT REGISTERED, if you get a result, check what they are registered for. Please be aware that gardeners register under the Chambre de Commerce and pay lower cotisations, this means that they are not and can not be registered for building unless they reregister with the Chambre de Metiers.

4) Just another caution. PROJECT MANAGERS – these can be legitimately registered, but this does not mean they are capable of doing building work themselves. A good project manager will charge you a fee to take the worry and stress out of finding artisans to do your work. This is time consuming and the project Manager earns his fee this way and gives the client piece of mind. However, some Project Managers are getting devis from Artisans using these to get clients to pay for works, hiring in cheaper workers, some clandestine, then pocketing the difference between the amount charged to the client and the amount paid to the workers. Clients should pay there artisans directly in order for the insurance to be valid and pay the fees required by the Project Manager direct to him. Again the rules regarding accidents and death will apply to the houseowner if anything happens. Project managers do not necessarily hold the qualifications or insurance to insure your works. So always double check and use sites like these to RECOMMEND the Project Managers who deserve recognition.