Our assistance was connected with a PPP investment project ran by the City of Kraków which involved building and maintenance of a tram line and a tram line tunnel. We supported the city in the transaction by, among other things, conducting pre-implementation analyses and market testing, helping select a private partner through a competitive dialogue and advising on the closing of the financing deal. As part of our assistance, we constructed a financial model comparing the PPP option with the traditional way of financing under a public sector comparator model (PSC). Its purpose was to confirm the rationale of opting for the PPP arrangement. The key objective was to find the boundary conditions for project bankability and profitability from the Private Partner’s perspective, taking into account specific corporation tax and VAT requirements, and the analysis of the potential contractor and financing institutions market. The model was set up to compare various options of external financing (including an EU grant for the Public Partner) and risk distribution.