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. NPAs are a key component of the North American Numbering Plan (NANP), a standardised telephone numbering system used across North America, the Caribbean, and some Pacific territories.

For mobile marketers, NPA codes can help identify the location of subscribers or potential customers so that they can segment their target audience to deliver:

  • Geotargeted messages
  • Event notifications
  • Personalised in-store offers
  • Other geotargeted messages

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, North American 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 can span anywhere between 2 to 5 digits.

3. Easily recognisable codes

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

What are NPA codes used for?

NPA codes stand for one of two things:

  • 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.
  • Toll-free numbers: In NANP, toll-free numbers start with the 8XX prefix and include 800, 833, 844, 855, 866, 877, and 888. Area codes 822, 880 through 887, and 889 are reserved for future use.

Ready to start geotargeting SMS subscribers based on area code? Sign up for Klaviyo and start sending targeted SMS messages today.

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