International accounting standard 17 „Leases“ was issued in 2001. as a replacement for International accounting standard 17 „Accounting for leases“ which was first introduced in 1987. In the first decade of 21. century entrepreneurs have abandoned former conservativ way of using asset so the idea of the operating lease became more and more popular. Precisely because of this, IAS 17 was no longer adequate because it required the presentation of only financial leases in the financial statements, and the IASB had to introduce a new standard that will be updated for the new market situation. In 2019, the IASB introduced the International Financial Reporting Standard 16 "Leases", which was aimed at correcting the mismatch between IAS 17 and market trends. The key change brought by IFRS 16 is the treatment of operating leases and leasing, according to which the lessee's company must present them in its financial statements. IFRS 16 introduces the concepts of "right-of-use assets" and "long-term lease liabilities" that lessees must introduce in their financial statements, not just in the notes to the financial statements as mandated by IAS 17. This has led to much more realistic and correct financial reporting because operating lease contracts are in practice concluded for a period longer than one year, which means that there is a long-term liabilities that leasee did not have to show in their financial statements until then. The standard paid special attention to the method of valuing existing leases and left lessees with the choice of how to value existing leases, thereby enabling them to choose their own accounting policies while respecting the already existing standards.