Subsequently, on 20 June 1948, the Reichsmark and the Rentenmark were abolished in the western occupation zones due to Soviet counterfeiting of AM-Marks resulting in economic instability and inflation and replaced with the Deutsche Mark issued by the Bank deutscher Länder (later the Deutsche Bundesbank).

Because the Reichsmark was still legal tender in the Soviet occupation zone, the currency flooded into the east from the west, where it was worthless.

As an emergency measure, many thousands of employees in the district offices started to affix adhesive coupons to those reichsmark and rentenmark banknotes for which the owners could prove their origin, up to a limit of 70 ℛ︁ℳ︁ per person.

However, due to limited convertibility and a restricted export profile, it was essentially worthless outside of East Germany.

Starting on 13 October 1980, Western visitors to the GDR were required to exchange a minimum of DM25 for East German marks per day.

Some exceptions were authorized: for example, tourists who booked hotel stays in the GDR that were paid in hard currency were exempted from the minimum exchange requirements.

At other times, West Berliners, retirees, children, and youth were granted either exemptions or were authorized reduced minimum exchange amounts.

The East German mark could not be spent in Intershops to acquire Western consumer goods; only hard currencies or Forum checks were accepted.

Upon adoption of the Deutsche Mark in East Germany on 1 July 1990, the East German Mark was converted at par for wages, prices and basic savings (up to a limit of M 4,000 per person, except a smaller number for children and a larger number for pensioners).

Almost all the paper money (about 100 billion Marks, in 620 million banknotes with a volume of 4,500 m3 (160,000 cu ft), about 300 boxcars), including all the currency collected at the time of the monetary union and the never-used East German M200 and M500 banknotes, was placed into storage in 1990 and 1991 in two 300-metre (980 ft) long sandstone caverns in the Thekenberge near Halberstadt.

In total, 3,000 tonnes of banknotes, passbooks, and checks were stored there, having been brought by military convoy from the Staatsbank der DDR in Berlin.

The 13 km (8.1 mi) tunnel system had been built by forced labour during World War II, and used by the National People's Army under the code name "Malachit", or camp complex KL-12 NVA-Nr.16/630.

[citation needed] In July 2001, it was discovered that two Halberstadt residents (aged 24 and 26) had gained entry to the tunnel system through an unsecured opening and made off with numerous banknotes.

In 1980, East Germany prepared special military banknotes intended to be used in international missions of the National People's Army (NVA), but they were never issued.

Instead, in 1990 and 1991, these and other old and unissued East German notes and coins were stored in bunkers in massive sandstone caverns in the Thekenberge near Halberstadt.