Area Code 31 – Dunajska Streda

Geographic Coverage and Administrative Jurisdiction

The +421 31 country-code prefix is a geographic National Destination Code (NDC) assigned to the Dunajská Streda area in the Trnava Region of western Slovakia. This numbering area covers the town of Dunajská Streda and its surrounding municipalities within the Dunajská Streda District, a territory situated on the Danubian Lowland near the Hungarian border. The region is part of the historical Žitný ostrov (Rye Island), the largest river island in Europe, bounded by the Danube and Little Danube rivers. Administratively, the code serves the district's fixed-line PSTN and VoIP subscribers, including residential, business, and public-sector lines.

Dialing Formats and Caller Instructions

Within Slovakia, calls to numbers in the 31 area require national trunk prefix 0 followed by the NDC and the subscriber number. The standard national format is 0 31 XXX XXXX, where the subscriber number typically consists of seven digits. For example, a local call would be dialed as 031 123 4567.

For international callers, the format is +421 31 XXX XXXX (or 00421 31 XXX XXXX from countries using the international prefix 00). For instance, a caller from abroad would dial +421 31 123 4567 to reach a fixed line in Dunajská Streda. When dialing from a mobile phone, the plus sign (+) is typically used to denote the international access code.

Overlay and Numbering Considerations

As of the latest ITU-T E.164 national numbering plan updates, the 31 NDC does not have an overlay code; the area is served exclusively by this single geographic prefix. Subscriber numbers are seven digits long, and the total length of a national significant number (NSN) is nine digits (including the leading 0 for national dialing). No premium-rate or special-service numbers are included within this geographic range.

Practical Guidance for Local and Foreign Callers

Local callers within the same NDC can often dial only the seven-digit subscriber number without the trunk prefix, depending on their operator's dialing plan. However, for clarity and to avoid misdialing, it is recommended to use the full national format. Foreign callers should always drop the leading 0 of the national prefix when using the international format. For example, to call a business in Dunajská Streda from the United States, one would dial 011 421 31 123 4567.

If you are unsure about the exact subscriber number, consult the official Slovak Telecommunication Office (Úrad pre reguláciu elektronických komunikácií a poštových služieb) database or your service provider's directory assistance.