External teams on Belgian sites: documentation is only one part
Limosa, social security and site registration are context-specific. Operational control matters too.
Look at the actual arrangement
Belgian rules distinguish a genuine service or subcontracting arrangement from hiring out workers. The day-to-day division of instructions and supervision matters. A label in a contract alone does not settle the question.
Map the formalities
Posting, Limosa, A1, sector rules and presence registration may apply differently across assignments. A Limosa receipt is evidence of a declaration, not proof that every other requirement is met.
Connect compliance with site planning
Confirm induction, safety rules, permits, protective equipment and the responsible contact on both sides. Seek specialist advice for the exact arrangement before work begins.
A useful pre-start conversation
Before an external team starts, identify who employs or contracts each person, who allocates tasks, who may give day-to-day instructions and who carries the work result. Confirm the site contact, safety induction, permits and any subcontracting chain. These facts help advisers assess the appropriate model; calling an arrangement ‘subcontracting’ in a document does not decide its legal character.
Treat each document for what it is
A Limosa-1 certificate evidences a declaration. An A1 certificate addresses which social security system applies for a period. Presence registration may be required on qualifying sites. None of these alone resolves contract classification, pay, working time, right to work or safety duties. Requirements and the Checkinatwork system can change, so verify current official guidance for the sector and start date before mobilisation.