The subject of research in this thesis are long-term sources of funding for the purpose of improving the business of the company. Long-term financing is one of the main sources and the basic function of any modern company. In addition to long-term sources, the company can at any time opt for those sources that we classify as short-term. Therefore, before making a final decision, the circumstances and the amount of investment in a new entrepreneurial venture should be considered in order to ultimately choose the option that will do the least harm to the current situation, and which will bring the greatest benefit in the future. In addition to choosing between short-term and long-term financing, it is important to consider the possibilities of financing from own sources, and only if this is not an option to resort to borrowing from external (foreign) sources. Long-term financing is usually used to finance fixed assets whose depreciation period is longer than 5 years (eg purchase of machinery, new business premises, expansion of the production line, etc.). When it comes to long-term loans, the entrepreneur uses them only when his own funds are not enough, and in most cases he decides on long-term bank loans. Banks give all their clients the opportunity to choose the loan repayment model that suits them best at that time. In modern financing through loans from banks in Croatia, the most popular are the loan repayment model with equal annuities and the loan repayment model with equal repayment quotas, so the greatest emphasis in this thesis is placed on these two models whose differences are explained and supported by examples.