IntroductIon Dear Readers and Authors, We present to you the first issue of 2019 of the scientific quarterly Copernican Journal of Finance & Accounting. At the beginning I would like to give special thanks to the Authors, Reviewers, Members of the Scientific Council, the Edito- rial Team and to everyone, who has contributed to the continuous development of the journal. Scientists from various universities present themes related to the different challenges of contemporary finances. In the current issue you can read articles about the scope of mobile banking applications use among retail bank custom- ers in Poland, and about the effect of social capital on operational performance in commercial banks in Erbil, the city in Iraq. One of the articles is devoted to the effect of mandatory dividend policy on agency costs of listed companies in China. You will be able to find an article about traditional fiscal devices in Po- land and the concept of their modernization. The subject of another article con- cerns the impact of economic aspects on the decision-making process on mod- ernization of heating sources used by households in Poland. The Copernican Journal of Finance & Accounting is open to all scientists from all countries and universities who conduct research in the area of inter- est of our journal. As always I encourage you to read and publish in our journal. Yours sincerely, Executive Editor, Dorota Krupa, Ph.D.