Area Code 91 – Mobile Network
The phone area code for Mobile Network is 91 (international format +35191). Browse local exchange codes (NXX) and carrier assignments below.
📞 Exchange Codes (NXX) for Area Code 91
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Overview of Portugal's +351 91 Mobile Prefix
The +351 91 prefix is a non-geographic mobile network code assigned within Portugal's national numbering plan, as administered by ANACOM (Autoridade Nacional de Comunicações). Unlike geographic area codes tied to specific cities or districts, the 91 prefix is allocated to mobile services, enabling subscribers to use their numbers anywhere in the country and, with roaming agreements, internationally. The prefix is part of the E.164 international numbering standard, ensuring global interoperability.
In Portugal, mobile numbers begin with '9' and are followed by two additional digits that identify the network operator. The 91 prefix is predominantly associated with Vodafone Portugal, one of the country's major mobile network operators (MNOs). However, due to mobile number portability (MNP), a subscriber may retain their 91 number even if they switch to another operator. Therefore, while 91 numbers historically originate from Vodafone, they are now operator-neutral in practice.
Dialing and Number Format
Portuguese mobile numbers are nine digits long, including the leading '9'. The international format for a 91 number is +351 91 XXX XXXX, where 'X' represents the subscriber's unique digits. When dialing domestically, callers must include the national trunk prefix '0' before the number, resulting in 091 XXX XXXX. For example, a typical Vodafone mobile number might appear as +351 91 234 5678 internationally or 091 234 5678 within Portugal.
For international callers, the correct sequence is:
- International access code (e.g., 00 from most countries, or '+' from mobile devices)
- Portugal's country code: 351
- The mobile number without the leading '0'
Thus, to call a Portuguese mobile with the 91 prefix from abroad, you would dial +351 91 234 5678.
Regulatory and Technical Considerations
As a non-geographic prefix, 91 numbers are not tied to a physical location, making them ideal for mobile users who travel frequently. The numbers support full PSTN and VoIP interconnectivity, and are used for both voice and SMS services. Since the implementation of MNP, routing is determined by a central database, ensuring that calls to 91 numbers are correctly directed regardless of the current network operator.
For businesses, 91 numbers are often used for customer contact, but they are not considered geographic for marketing or emergency services purposes. Emergency calls (112) are always routed based on the caller's location, not the number prefix. When dialing a 91 number from a fixed line in Portugal, the same trunk prefix '0' is required, and call charges may vary depending on the caller's plan.
In summary, the +351 91 prefix is a vital component of Portugal's mobile communications landscape, offering reliable, portable, and location-independent connectivity for millions of users.