From Annex I:

Travel costs will be compensated according to the internal rules and regulations of the travelers' home institutes. The home institutes will then bill the Project Coordinator for the travel occurred. The amounts will depend on the sites where the network will meet, and can be decided only after the plan of the meetings has been agreed upon. The coordinating partner, University of Helsinki, will hold travel allowance for all partners, and the actual compensations will be made by the University of Helsinki.

Address to where cost claims should be sent is:

    Riitta Ulmanen
    Department of Mathematics and Statistics
    P.O. Box 68 (Gustaf Hällströmin katu 2b)
    FI-00014 University of Helsinki

In other words, each participant gets his or her travel costs paid by his or her own institute according to the rules of the institute in question. Then, the institute will send a bill to University of Helsinki and keep the original receipts. For the final audit, University of Helsinki will produce the bill from the institute who has already paid the participant.