Equal in importance to the legal was the commercial reform, for this was the condition for building up the material prosperity of the country. Germany was a poor country, but the poverty was to a great extent the result of political causes. Communication, trade, manufactures, were impeded by the political divisions, and though the establishment of a customs union had preceded the foundation of the empire, the removal of other barriers required imperial legislation. A common system of weights and measures was introduced in 1868. The reform of the currency was the first task of the empire. In 1871 Germany still had seven different systems; the most important was the _Thaler_ and the _Groschen_, which prevailed over most of North Germany, but even within this there were considerable local differences. Throughout the whole of the south of Germany and in some North German states the gulden and kreuzer prevailed. Then there were other systems in Hamburg and in Bremen. Everywhere, except in Bremen, the currency was on a silver basis. In addition to this each state had its own paper money, and there were over 100 banks with the right of issuing bank-notes according to regulations which varied in each state. In 1871 a common system for the whole empire was established, the unit being the _Mark_ (= 11¾d.), which was divided into a hundred _Pfennige_: a gold currency was introduced (_Doppel-Kronen_ = 20 _M._; _Kronen_ = 10 _M._); no more silver was to be coined, and silver was made a legal tender only up to the sum of twenty marks. The gold required for the introduction of the new coinage was provided from the indemnity paid by France. Great quantities of thalers, which hitherto had been the staple of the currency, were sold. The right of coinage was, however, left to the individual states, and as a special concession it was determined that the rulers of the states should be permitted to have their head placed on the reverse of the gold coins. All paper currency, except that issued by the empire, ceased, and in 1873 the Prussian Bank was converted into the Imperial Bank (Reichsbank).
Closely connected with the reform of the currency and the codification of the commercial law was the reform of the banking laws. Here the tendency to substitute uniform imperial laws for state laws is clearly seen. Before 1870 there had been over 100 banks with the right of issue, and the conditions on which the privilege was granted varied in each state. By the Bank Act of March 14, 1875, which is the foundation of the existing system, the right of granting the privilege is transferred from the governments of the states to the Bundesrat. The existing banks could not be deprived of the concessions they had received, but unless they submitted to the regulations of the new law their notes were not to be recognized outside the limits of the state by which the concession had been granted. All submitted to the conditions except the Brunswick Bank, which remained outside the banking system of the empire until the Bank Act of June 5, 1906, was passed, when it surrendered its right to issue notes. The experience of Germany in this matter has been different from that of England, for nearly all the private banks have now surrendered their privilege, and there remain only five banks, including the Reichsbank, which still issue bank notes. The other four are situated in Bavaria, Saxony, Württemberg and Baden. The total note-issue was fixed by the law of 1875, a proposal being assigned to each bank. Any part of this issue assigned to private banks which might be withdrawn from circulation, owing to a deficiency in the legal reserve funds, was to be transferred to the Reichsbank. The result has been the tendency of the latter gradually to absorb the whole note-issue. By the law of 1906 the Reichsbank was authorized to issue 20 M. and 50 M. notes. Treasury notes (_Reichs-Kassenscheine_) for these amounts were no longer to be issued; but the state reserved the right to circulate notes of the value of 5 M. and 10 M.