From the time of its creation in 1880, the Bank of Rome has never operated solely in Italy itself. Its formal presence abroad began twenty-two years after its foundation when in 1902 an agency was opened in Paris. Despite this relatively late start, the next twelve years were to witness a considerable expansion in the number of the Bank's foreign agencies and branches. Following the branch in Paris came further agencies in Malta; then at Cairo and Alexandria in Egypt; at Tripoli, Benghazi and Derna in Libya; at Barcelona, Tarragona and Montblanch in Spain; and at Constantinople in the Ottoman Empire. There were also plans in 1910 to open a branch at Jerusalem, but these were not realized until after the First World War and the division of the Turkish Empire.

Not all of these branches were engaged in investment operations, and the Bank's particular ties with the Roman Catholic Church meant that one of their principal functions was to safeguard the deposits and savings of local Catholic corporations (monasteries, churches, confraternities, etc.) and the Catholic communities that gravitated around them. The Malta agency was typical of this type. But more often the links with the Church provided opportunities for investment as well as attracting savings, and the Bank's agencies provided long- and short-term loans. In Paris, for example, the agency began to attract an increasingly large share of the savings of French Catholics, taking over at least in part the function of Bontoux's Union Générale that had crashed in 1882.