Slovak Telecom will begin its 3G shutdown on October 3.
The Slovakian operator will begin its switch-off in the districts of Zlate Moravce and Zarnovica ahead of a gradual region-by-region closure.
The full shutdown of its 3G network is expected to be complete by the end of the year.
Slovak Telecom, which is wholly owned by Deutsche Telekom, will then repurpose the spectrum towards its 4G and 5G services.
Domestic rival Orange Slovakia is also planning to call time on its 3G service by the end of this year.
The operator announced last December that it will switch off its 3G network a year ahead of schedule, after initially earmarking the switch-off for 2024.