What is a numbering plan area?

A Numbering Plan Area (NPA), also known as an area code, is typically a 3-digit code that identifies a telephone service region within a country. It is a key component of the North American Numbering Plan (NANP), a standardized telephone numbering system used across North America, the Caribbean, and some Pacific territories.

NPA codes help you identify the location of your subscribers or potential customers and segment your target audience to deliver:

  • Geotargeted messages
  • Event notifications
  • Personalized offers

Types of NPA codes

NPA codes can have several formats depending on where and how they are used:

1. Fixed length NPA code

Some telephone numbering plans specify NPA codes with the same length. For instance, NANP NPA codes have a fixed 3-digit length.

2. Variable length NPA codes

Several countries, such as the UK, Germany, and Japan, use NPA codes that vary in length. These codes have no prescribed limit and can span anywhere between 2 to 5 digits.

3. Easily recognizable codes

Easily recognizable codes (ERCs) are 3-digit NANP NPA codes where the last 2 digits are identical to make them easier to dial and remember, such as 866 for toll-free service.

What are NPA codes used for?

1. Geographic location

The general role of the NPA is to divide a country’s numbering system into smaller geographic regions by assigning a unique number to each area within that country. 

This division helps you identify your audience’s location based on the destination number, which allows you to understand them better and adjust your approach.

2. Toll-free numbers

Toll-free numbers have a 3-digit NPA code. In NANP, toll-free numbers start with the 8XX prefix and include the following numbers: 

  • 800, 833, 844, 855, 866, 877, and 888

You can use toll-free numbers to communicate with your customers without incurring long-distance charges.

Ready to start using NPA codes to support your mobile marketing initiatives? Sign up for Klaviyo and start sending targeted SMS messages using extensive subscriber profiles, customer segmentation, and automated flows that trigger personalized customer interactions. 

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