The National reference rate (NRR) of the average cost of financing of the Croatian banking sector is an implicit interest rate computed and published by the Croatian National Bank on its website pursuant to Article 306, paragraph (3) of the Credit Institutions Act (Official Gazette 159/2013, 19/2015, 102/2015, 15/2018, 70/2019, 47/2020, 146/2020 and 151/2022) and Article 60 of the Act on the Introduction of the Euro as the Official Currency in the Republic of Croatia (Official Gazette 57/2022 and 88/2022). It serves the role of an index for determination of the variable part of the variable interest rate on consumer credit in accordance with Article 59, paragraphs (1) and (2) of the Act on the Introduction of the Euro as the Official Currency in the Republic of Croatia for consumer credits granted before 1 January 2023.

The NRR is the rate of the average cost of funding of the Croatian banking sector (banks, savings banks and branches of foreign banks), given the reference period under review (3, 6 or 12 months), the relevant currency (EUR and USD) and the scope of funds (1 – for funds of natural persons, 2 – for funds of natural persons and legal persons from the non-financial sector, and 3 – for all funds received from all natural and legal persons).

The name of each NRR clearly indicates the scope of funds(1, 2 or 3), the duration of the reference period to which the original data based on which the NRR is computed refer (3M, 6M or 12M) and the currency of funds (EUR, USD), a total of 12 indices (NRR1 and NRR2 are not computed for USD). Funds in euro indexed to the US dollar are included in the US dollar funds. For instance, the six-month NRR computed on the basis of data on the funding of natural and legal persons denominated in US dollar and in euro with a currency clause in US dollars is indicated as "6M NRR3 USD".

By the reporting date of 31 December 2019, the NRR was computed and published by the Croatian Banking Association based on statistical data published by the CNB in the file Table SP5 Costs of banks’ funding. As of the reporting date of 31 March 2020, data on the NRR have been computed by the CNB and published on its website in the file National reference rate (NRR).

The CNB stopped computing the NRR for the Swiss franc as it accounted for a small share in financial instruments and due to the non-representativeness of the data based on which it was computed. The last computation quarter for which the NRR for the Swiss franc was published was the second quarter of 2022. Pursuant to the Act on the Introduction of the Euro as the Official Currency in the Republic of Croatia, after 2022, the CNB ceased to compute the NRR for the kuna, but it provisionally included the relevant kuna items in the NRR computation for the euro throughout 2023. The last computation quarter for which the CNB published the NRR for the kuna was the third quarter of 2022.