The registers set up under Sixtus V show the existence of 279 Jewish banks in 131 places in Italy in about 1600. In fact, there were certainly considerably more. In the first place, it would seem that a certain number of banks were operating without papal authorisation. This emerges particularly from the 'absolutions' which, together with patents proper, the cardinals camerlengo were issuing post facto to banks which were already in operation. But above all it can be concluded that in certain cases a single entry in the register or on the patent was sufficient to cover the functioning of a whole group of banks. In the majority of cases, it is not possible to know if the entry corresponds to a single bank or to several.