Area Code 21 – Bucharest and Ilfov County

Overview of Romania's +40 21 Geographic Prefix

The +40 21 country-code prefix is the geographic area code assigned to Bucharest, the capital of Romania, and the surrounding Ilfov County. This allocation follows the ITU-T E.164 international numbering plan and the national numbering regulations enforced by the Romanian Authority for Digitalisation (ADR). The prefix is used for fixed-line (PSTN) services, including traditional copper lines, ISDN, and increasingly, fixed wireless and VoIP-based local access services that are registered to a physical address within the coverage area.

Coverage and Administrative Jurisdiction

The 21 area code covers the entire municipality of Bucharest, which is administratively divided into six sectors (Sector 1 through Sector 6), as well as the localities in Ilfov County, such as Otopeni, Bragadiru, Chitila, Măgurele, and Voluntari. This region is the economic and political hub of Romania, hosting the headquarters of most national and multinational companies, government institutions, and major financial centers.

Dialing Formats and Caller Instructions

For callers within Romania, the national trunk prefix is 0. To call a Bucharest fixed line, you must dial 021 followed by the 7-digit subscriber number. For example, a local Bucharest number might be 021 123 4567. When dialing from a mobile phone within Romania, the same format applies: 021 + subscriber number.

For international callers, the Romanian country code is +40. The leading '0' of the national prefix is dropped. Therefore, the same number is dialed as +40 21 123 4567. This format is essential for all international voice calls, SMS (if supported), and fax transmissions.

Numbering Structure and Overlay Considerations

Romanian fixed-line numbers are 9 digits long, including the area code. The structure is: 0 (trunk prefix) + 21 (area code) + XXXXXXX (7-digit local number). There is no overlay code for Bucharest; the 21 prefix is the sole geographic code for the capital region. However, due to number portability, a number starting with 021 may be routed to a mobile network or a VoIP provider if the subscriber has ported their number. Conversely, a number originally assigned to another region could be ported to a Bucharest address, but the prefix remains unchanged.

Practical Implications for Businesses and Residents

Having a 021 number is often seen as a mark of business credibility and local presence. For companies, a Bucharest number is crucial for customer service and administrative operations. When calling from abroad, it is important to use the full international format to avoid misrouting. Additionally, some VoIP providers may offer virtual numbers with the 021 prefix, allowing businesses to establish a Bucharest presence without a physical office, but these services must comply with Romanian numbering regulations.