EUOSHA/2021/OP/F/SE/0142  information provided can be further updated or re-used by the participant in other European Commission  calls for tenders or calls for proposals.   Please provide information about the SME status of the participant in the Participant Register by filling in  the SME Declaration section in the Participant Register. The section becomes available only when  updating/modifying the details of the registered organisation.  At any moment during the procurement procedure, the Research Executive Agency Validation Services  (hereafter the  EU Validation Services)  may contact the participant and ask for supporting documents on  legal existence and status. The requests will be made through the register's messaging system to the email  address of the participant's contact person indicated in the register. It is the responsibility of the participant  to provide a valid email address and to check it regularly.  The documents that may be requested by the  EU Validation Services  are listed in the EU Funding and  Tenders Rules for Legal Entity Validation, LEAR Appointment and Financial Capacity Assessment.   Please note that a request for supporting documents by the  EU Validation Services  in no way implies that  the tenderer has been successful.  Economic operators can submit a tender either as a sole tenderer or as a group of tenderers. In either  case, subcontracting is permitted. In order to fulfil the selection criteria set out in  section 4.2 , the tenderer can rely on the capacities of  subcontractors or other entities (not subcontractors).  The role of each entity involved in a tender (hereafter referred to as  involved entity ) must be clearly specified  in the eSubmission application: (i) sole tenderer, (ii) group leader of a group of tenderers, (iii) member of a  group of tenderers or (iv) subcontractor. For an entity (that is not a subcontractor) on whose capacities the  tenderer relies to fulfil the selection criteria, this role is defined in the commitment letter ( Annex IX-2 ). This  applies also where the involved entities belong to the same economic group.  A joint tender is a situation where a tender is submitted by a group (with or without legal form) of  economic operators regardless of the link they have between them. The group as a whole is considered  a tenderer. All members of the group assume joint and several liability towards the  contracting authority  for the  performance of the contract as a whole. Group members must appoint a group leader and a single point of contact authorised to act on their  behalf in connection with the submission of the tender and all relevant questions, clarification requests,  notifications, etc., that may be received during the evaluation and award, and until contract signature.  The model of power of attorney attached in  Annex VIII  is to be used.  The joint tender must clearly indicate the role and tasks of each member and of the group leader, who  will act as the  contracting authority's  contact point for the contract's administrative or financial aspects  3.4.1  Joint tender  3.4  Ways to submit a tender  42 