Antwerp (BE), Lausanne (CH), Madrid (ES), Prague (CZ), Stockholm (SE), December 6, 2011 – The Payroll Services Alliance welcomes two market leaders in its network of European payroll services providers: Seresco (Spain and Portugal) and Trianon (Switzerland). With the accession of Seresco and Trianon, the Payroll Services Alliance now covers 27 European countries.