Reviewed by Roksolana Pyrtko
The certificate of the Statistical Office of the SR of 15 January 2026 states average inflation for 2025 of 4,0 %; Eurostat’s harmonised index gave 4,2 % for Slovakia and 2,1 % for the euro area. An indexation clause would have produced a different figure from the same data depending on which index and which period it names: on every 100 € of monthly rent, that is the difference between 4,00 € and 2,10 €.
In 2026 the order of these indices does not hold. In August 2026 the euro area harmonised index reached 3,2 % year on year, while both the Slovak harmonised and the national index stood at 3,1 %. The flash estimate for September 2026 of 2 October gives 3,8 % for the euro area and 3,1 % for Slovakia; the final data come out on 15 and 16 October. On the average of the last twelve months, Slovakia is still higher as at August, 3,9 % against 2,5 %. Which of these numbers reaches the rent is decided by the text of the lease, not by statistics.
Rent indexation rests on two registers: the CPI of the Statistical Office of the SR and Eurostat’s HICP
Rent indexation in Slovakia can rely on two public registers kept by two institutions. The Statistical Office of the Slovak Republic publishes the national consumer price index and once a year issues a certificate of average annual inflation. Eurostat publishes the harmonised index of consumer prices for Slovakia and for the euro area in a single dataset. Neither of these publications shows all three series side by side.
The national index, abbreviated CPI, is published monthly by the Statistical Office of the SR. The latest information report for August 2026 on the national index came out on 15 September 2026 and gives year-on-year inflation of 3,1 % and a total for the first eight months of the year of 3,6 %. According to the same report, the national index also includes the item of imputed rent, which the harmonised index does not.
The harmonised index, abbreviated HICP, is compiled by every European Union member state under common rules, and Eurostat builds the euro area aggregate from it. Dataset prc_hicp_minr, updated on 2 October 2026, contains for both Slovakia and the euro area index levels on the 2025 and 2015 bases, annual rates and the twelve-month moving average, from January 2025 to August 2026 and a flash estimate for September 2026.
The summary table below takes from both registers four ways of calculating the change from the indices: the full-year average, the year-on-year change for December, the year-on-year change for the latest closed month and the average of the current year; it adds the flash estimate for September 2026. Two cells that no register publishes directly are own calculations from index levels and are marked as such.
Summary table: three inflation indices, five periods, a cut-off date for each column
The national index of the Statistical Office of the SR, the harmonised index for Slovakia and the harmonised index for the euro area differ by period and, since August 2026, rank differently. For 2025 and December 2025 the euro area is 1,8 to 2,1 percentage points below the Slovak indices. In August 2026 it is highest, on the January to August average lowest, and in the September estimate 0,7 points above Slovakia.
| Period | CPI Slovakia, ŠÚ SR (as at 15. 1. and 15. 9. 2026) | HICP Slovakia, Eurostat (as at 2. 10. 2026) | HICP euro area, Eurostat (as at 2. 10. 2026) |
|---|---|---|---|
| Average of 2025 against 2024 | 4,0 % | 4,2 % | 2,1 % |
| December 2025 against December 2024 | 3,8 % | 4,1 % | 2,0 % |
| August 2026 against August 2025 | 3,1 % | 3,1 % | 3,2 % |
| January to August 2026 against the same period of 2025 | 3,6 % | 3,7 % (own calculation) | 2,7 % (own calculation) |
| September 2026 against September 2025 (flash estimate) | release on 15. 10. 2026 | 3,1 % (estimate) | 3,8 % (estimate) |
The 2025 average for the harmonised indices is the twelve-month moving average to December 2025 as kept by Eurostat. The own calculation in the January to August row divides the average of the 2025=100 indices for January to August 2026 by the average for January to August 2025: for Slovakia 103,30 to 99,58, for the euro area 102,36 to 99,71. The Statistical Office of the SR gives 3,6 % directly for the national index over the same period. The row for September contains a flash estimate, which may change with the final data of 15 and 16 October.
The national index column combines two publications. The 2025 values come from January 2026, that is, from before the classification change, and the 2026 values already from the new classification. The harmonised columns come from a single dataset with a single update date, recalculated back into the new classification for 2025 as well.
2025: national CPI 4,0 %, Slovak HICP 4,2 %, euro area 2,1 %
For 2025 the national consumer price index of the Statistical Office of the SR gave average annual inflation of 4,0 %, the harmonised index for Slovakia 4,2 % and the harmonised index for the euro area 2,1 %. Year on year for December 2025 the figures were 3,8 %, 4,1 % and 2,0 %. These numbers were available for the January rent indexation in 2026.
The Statistical Office of the SR confirmed the 4,0 % value in a separate document. The Certificate of the inflation rate in the SR dated 15 January 2026 states that inflation measured by the consumer price index reached an average of 4,0 % in 2025 against the previous year. It is the only one of the three figures that takes the form of a signed certificate rather than just a database row.
The year-on-year value for December 2025 is contained in table sp0029ms of the Statistical Office of the SR, updated on 15 January 2026: an index of 103,8 with the same month of the previous year equal to 100. The same table gives 104,0 for the full-year total, the same 4,0 % as the certificate. The difference between the December and the average value is 0,2 percentage points for the national index.
Between the national and the harmonised index for Slovakia, the 2025 difference is 0,2 points on the average and 0,3 points in December. Both indices measure prices on the same territory but differ in their baskets. The harmonised index excludes imputed rent and selected items of major repairs and maintenance of dwellings, and therefore also has different weights for the remaining groups.
Between the Slovak and the euro area harmonised index, the difference is 2,1 points both on the average and in December. A clause tied to the euro area would therefore have raised rent in January 2026 by half of what a clause tied to the Slovak harmonised index would. On rent of 100 € a month, that is 2,10 € against 4,20 €, and 4,00 € under the national index.
The euro area overtook Slovakia in August 2026 for the first time since January 2025
In August 2026 the euro area harmonised index reached 3,2 % year on year, the harmonised index for Slovakia 3,1 % and the national index of the Statistical Office of the SR also 3,1 %. It is the first month in the series since January 2025 in which the euro area annual rate is higher than the Slovak one. The twelve-month average meanwhile remains 3,9 % in Slovakia and 2,5 % in the euro area.
According to the Eurostat dataset, the euro area stood at 3,2 % in August after 2,9 % in July and 2,0 % in August 2025. For Slovakia the dataset gives 4,4 % in August 2025, 3,2 % in July 2026 and 3,1 % in August 2026.
The flash estimate for September 2026, which Eurostat published on 2 October 2026, gives the euro area 3,8 % after 3,2 % in August; energy had the highest annual rate, 18,8 % after 14,3 % in August. For Slovakia, the Statistical Office of the SR gives 3,1 % in its flash estimate of the same day, the same as in August, with prices up 0,2 % month on month. The gap between the euro area and Slovakia widens to 0,7 percentage points in the estimate; the final September data come out on 15 and 16 October.
The two series reached the August value by opposite routes. The Slovak harmonised index rose by 2,0 % in January 2026 against December and moved only by tenths in the following months. The euro area harmonised index fell by 0,6 % in January and gained most in March and April, by 1,3 % and 1,0 % a month.
In its August report, the Statistical Office of the SR attributes the Slovak development mainly to the division of housing, water, electricity, gas and other fuels, which was 7,4 % more expensive year on year because of regulatory measures introduced in January, and to motor fuels, up 17,4 %. This division makes up the largest share of household expenditure, 21,8 %. Food and non-alcoholic beverages, by contrast, were 2,5 % cheaper and make up the second-largest share, 20,9 %.
For rent indexation this yields a simple reading rule. The January jump of the Slovak index is contained in every year-on-year comparison up to December 2026, because all of them compare the 2026 level with the 2025 level. The year-on-year value for a single month and the twelve-month average therefore give Slovakia and the euro area the opposite order in 2026.
January to August 2026: average 3,7 % versus 2,7 %, since December 2,8 % versus 3,0 %
Over the first eight months of 2026 the harmonised index for Slovakia was on average 3,7 % higher than in the same period of 2025 and the euro area harmonised index 2,7 % higher, both values being own calculations from Eurostat data. The national index of the Statistical Office of the SR gave 3,6 % for the same period. From December 2025 to August 2026, however, the euro area rose more.
The change since December is shown by the 2025=100 index levels in the Eurostat dataset. The Slovak harmonised index stood at 100,75 in December 2025 and at 103,60 in August 2026, a rise of 2,8 %. The euro area index stood at 100,63 and 103,69, a rise of 3,0 %. Both figures are own calculations from the levels given.
Each way of calculating gives a different number from the same data. Comparing the annual average with the previous year’s average gives the euro area a lower number than Slovakia in 2026. Comparing the index level at the last indexation with the level at the new indexation works with the movement since December, and that is so far higher in the euro area.
The twelve-month moving average, which Eurostat publishes as a separate indicator, was 3,9 % for Slovakia and 2,5 % for the euro area in August 2026. For Slovakia it is gradually falling from 4,2 % in December 2025, for the euro area it is rising from 2,1 %. The value of this indicator for December 2026 will be the average annual rate for 2026 against 2025.
New 2025=100 base in the HICP and the end of the December 2000 base in the CPI
From January 2026 both registers changed their classification and base. The Statistical Office of the SR moved to the COICOP 2018 classification, new weights and a new base, and since January 2026 no longer publishes indices with the December 2000 base in its public database. Eurostat introduced the ECOICOP version 2 classification and the 2025=100 reference period, while the series on the 2015=100 base remains available.
For a clause that refers not to an inflation rate but to an index level with a specific base, this is a material difference. According to its August report, the Statistical Office of the SR has not published the national index with the December 2000 reference period in its public database since January 2026. Eurostat continues to maintain the harmonised index on the 2015 base, as it states on its Information on data page, where indices 2025=100 and 2015=100 are both available.
A change of base does not change the annual rate. For the Slovak harmonised index, the 2015=100 series gives 154,61 for August 2026 against 150,00 in August 2025, that is 3,1 %, the same as the 2025=100 series. For the euro area, 133,50 against 129,31 gives 3,2 %. Both values are own recalculations from the Eurostat dataset.
For the euro area, the composition also changed from January 2026. In its release of 2 October 2026, Eurostat states that data up to December 2025 represent the euro area with twenty members and data from January 2026 the euro area including Bulgaria, linked by a chain index. The series called euro area thus compares two different groups of countries within one year.
The harmonised index can be revised. On its data page Eurostat refers to Article 7(5) of Regulation (EU) 2016/792 and keeps a table of revisions, from which for example: on 3 March 2026 it corrected the euro area for January and February 2026 over a technical issue with the inclusion of Bulgaria, on 24 April 2026 it restored the original version of the first-released euro area data for January 2026, and on 20 May 2026 it changed the re-referencing to the 2015 base for series without data for 2015. The value a clause takes on the calculation date may therefore not be the same one the dataset shows a few months later.
What the data lack: a commercial rent index and the share of clauses
Neither the Statistical Office of the SR nor Eurostat publishes which index and which period commercial leases in Slovakia use. None of the sources in the Sources and verification table gives the share of clauses by type of index. The summary table therefore shows what numbers the individual clauses receive, not how much rent is paid under which of them.
An index of commercial rent itself is also missing. Imputed and actual rent in the national index concern household housing, not warehouses, halls or offices. The Statistical Office of the SR states in its August report that both items were higher year on year, but neither of them measures the rent that an indexation clause adjusts.
The national index in the new classification is not available month by month for 2025 in the office’s open interface. The December 2025 value in the table therefore comes from the older table dated 15 January 2026. A twelve-month moving average of the national index to August 2026 is not available in the office’s open publications as at 7 October 2026, and the summary table therefore has no such row.
Finally, the registers do not match in timing. Eurostat published the flash estimate for September 2026 on 2 October, and on the same day the Statistical Office of the SR issued its own for Slovakia, a product it added to its range from October 2026. The final data follow later: the national index for September on 15 October and the harmonised index on 16 October 2026. Until 15 October there is thus only an estimate of the harmonised index for September and no national index yet.
Sources and verification
| Indicator | Source | Note |
|---|---|---|
| Average annual inflation 2025 under the CPI | ŠÚ SR, Certificate of the inflation rate in the SR | 4,0 %, document of 15. 1. 2026 |
| CPI for December 2025 and the 2025 total | ŠÚ SR, table sp0029ms | Updated 15. 1. 2026, classification valid until December 2025 |
| CPI for August 2026 and for January to August 2026 | ŠÚ SR, information report for August 2026 | Published 15. 9. 2026, COICOP 2018 classification |
| HICP Slovakia and euro area, indices and rates | Eurostat, dataset prc_hicp_minr | Updated 2. 10. 2026 (September is an estimate), ECOICOP version 2, base 2025=100 and 2015=100 |
| HICP flash estimate for September 2026 and energy for August | Eurostat, Euro indicators; ŠÚ SR, flash estimate of harmonised inflation | Published 2. 10. 2026, estimate for the euro area and Slovakia |
| January to August 2026 average and change since December 2025 | Own calculation | From 2025=100 index levels in the Eurostat dataset, no external inputs |
Difference in definitions. The national consumer price index and the harmonised index for Slovakia cover the same territory, but the harmonised index excludes imputed rent and selected major dwelling repairs, and so has different weights. The annual average is the annual aggregate rate of year-on-year inflation for the national index and the twelve-month moving average for the harmonised one. The euro area has twenty countries up to December 2025 and twenty-one from January 2026.
For tenant, landlord and investor: decisions before January 2027
Before the January 2027 indexation, both registers will publish four more monthly values and one annual one; September is so far only a flash estimate. In its calendar of first releases, the Statistical Office of the SR has the national index for September 2026 on 15 October and the harmonised index for September on 16 October 2026. The office issued the certificate of average inflation for 2025 on 15 January 2026.
Tenant
For a tenant, the decisive element is the text of the tenant’s own clause: which of the three indices it names, whether it compares the annual average, December or the index level at the date of the last indexation, and whether it refers to the December 2000 base, which the national index has not had in the public database since January 2026. An occupancy cost budget for 2027 can only be built on the chosen type, and the values to August 2026 give only an interim state of it.
Landlord
For a landlord with several leases, what matters is that the same month gives a different ranking of indices in 2026 depending on the type of comparison. For clauses tied to an index level, the point to watch is whether the lease sets a replacement series when the base changes, and for the harmonised index also the date as at which the value is taken, since Eurostat revises its data.
Investor
For an investor comparing portfolio income under leases tied to the Slovak and to the euro area index, the signal is the path of the twelve-month average over the next four months. In August 2026 the Slovak average was higher by 1,4 percentage points, in December 2025 by 2,1 points. Final values for 2026 will come with the December data published in January 2027 and with the certificate of the Statistical Office of the SR on average annual inflation for 2026.
This material was reviewed by Roksolana Pyrtko, who is the CEO of the Lviv shopping and entertainment centers “Roksolana” and “Spartak”, an attorney, and a specialist in commercial real estate analytics and development.
This material is for information only and does not constitute legal, tax or financial advice.