This guide covers all the types of numbers Plivo offers. You can learn more about searching and buying numbers in the Plivo PhoneNumbers API documentation, and learn more about accessing the numbers already added to your account in the Plivo Numbers API documentation.

Understanding phone number types

Plivo offers phone numbers of three types: fixed, toll-free, and mobile. The phone number type can generally be identified using a phone number’s prefix, which it typically indicates the capability (receive call and/or SMS) and the region the phone number belongs to. (Phone number prefixes in the US and Canada don’t indicate type and capability, however.)

Evaluating phone number types

What type of phone number should you use? Consider:

  • Your use case
  • The cost you expect the dialer to incur
  • The expectation you want to set for the user you communicate with

Here are more details about fixed, toll-free, and mobile phone numbers, along with some discussion on the circumstances in which they should be used.

Fixed numbers

Fixed numbers are assigned to a specific region, which could be a city, an area, or a country. For instance, phone numbers in the format +1 (212) nnn-nnnn correspond to the Manhattan area in New York City, while +1 (917) nnn-nnnn numbers correspond to anywhere in New York City. Similarly, phone numbers in the format +33 5 nn nn nn nn correspond to the southwest France region and +33 9 nn nn nn nn correspond to the entire country of France.

Fixed numbers generally support receiving calls. In a few countries, such as the US and Canada, they may support SMS as well. Users dialing from within the phone number’s region are charged local rates. Individuals and local businesses that communicate with customers in a specific city or an area typically use fixed numbers that belong to the area. Larger businesses that engage with customers across a whole country should use fixed numbers with prefixes that are reserved for the entire country.

Toll-free numbers

Toll-free numbers, also called freephone numbers, are phone numbers that are billed to the called party for all incoming calls and are free of charge for the calling party. Most countries reserve a set of dialing prefixes, typically 1800 or 800, to denote toll-free services.

Toll-free numbers are generally used by businesses that want their customers to reach them at no cost. Businesses also use toll-free numbers to send transactional and promotional SMS messages to opted-in customers.

Mobile numbers

Mobile numbers are similar to the phone numbers connected to SIM cards used in cell phones. However, they can be used like fixed or toll-free numbers, and are not connected to any SIM card. Most countries assign a range of prefixes for mobile numbers, which lets these phone numbers be distinguished from other types of numbers. For instance, the prefixes +33 6 and +33 7 in France and +45 91 through +45 93 in Denmark are reserved for mobile numbers. Mobile numbers generally support sending and receiving SMS messages, and in some countries also support making and receiving calls.