The declaration to be made by the project owner or the instructing party, pursuant to the second paragraph of article L. 1262-4-1, when his co-contractor has not sent him the acknowledgement of receipt of the posting declaration for which he is responsible pursuant to the first paragraph of article L. 1262-2-1, shall be sent to the competent territorial unit mentioned in articles R. 1263-4-1 and R. 1263-6-1 using the “SIPSI” teleservice of the Ministry of Employment.
The declaration must be drawn up in French and must provide proof by any means giving it a date certain that it was made within the time limit laid down in article L. 1262-4-1.