From 1840 on, the year in which the postal administration was established in the Ottoman Empire, the building of the museum served as a centre providing postal services in the courtyard of Yenicami. The big wooden building in this area that had been used as a tax office was reorganised as ‘’the Grand Post Office’’, because it had a courtyard large enough to accommodate a great number of animals with a location near the trade centres and the promenade of the city. In 1870 the administrations for the postal and telegram services were reorganised into a single administration operating under a ministry, and the Grand Post Office was renamed into Post Office of Istanbul. As, over the course of time, this wooden building had failed to provide enough space both for the ministry agencies and postal services, a need arose for a bigger building. Thus this wooden structure was demolished in 1890, and the masonry building that houses the Isbank Museum today was built. The building was inaugurated on September 23, 1892.
In 1909 the Post Office of Istanbul was relocated to a new building, namely to that of Grand Post Office in Sirkeci, and the building in Yenicami continued to serve as “parcel post office” until 1917, the year in which the building began to serve as premises of Osmanli Itibar-i Milli Bank (Ottoman National Credit Bank) that was founded in that year.
In 1927 the building was transferred to Isbank when Itibar-i Milli Bank was merged with Isbank. After the transfer, the building had to undergo several renovations to reorganise it into a bank branch, in the course of which new office rooms were built to accommodate the personnel of the bank then numbering 70 employees. On February 28, 1928 the building was inaugurated as Isbank Istanbul Branch. As overtime new branches were opened in Istanbul in the 1950s, the branch was renamed into Yenicami Branch, under which it was used as a bank branch until 2004.
In 2005 a project was designed to reorganise the building into the Isbank Museum. During the reorganisation and restructuring of the building, all the fixed furnishings and details belonging to the original structure of the building were preserved in their original form as they were used in the bank branch, and only air-conditioning, security and illumination systems required for a functioning as a museum were added. The spaces in the basement where the Main Vault and Safe-Deposit Boxes had been held were reorganised to hold exhibitions, and one of the storerooms that served as an archive was restructured into a depot to store the collections and the other one into a hall to be used for workshop activities for 50 people.
The ground floor of the building has been designed as an exhibition hall, with all the counters and cashier’s desks preserved in their original form as they were used in the bank branch. This floor also hosts the bookstore of Isbank Kültür Yayınları. The rooms on the first floor, on the other hand, house exhibition halls for collections, offices and wet spaces.