When, in 1993, Czechoslovakia separated into two independent states, the Czech Republic and Slovakia, both republics incorporated Czechoslovak valid law into their legislation. As far as IP rights are concerned, the most important act was the Patents Act No 527/90. In the following years both republics were working on their own legislation and individual Trade Marks Acts were adopted. However, the work continued. International cooperation required substantial harmonization with legislation of the European Union and as far as patent law was concerned; the work was focused on substantial harmonisation with EPC.