521 Area Code
Personal communications services
The 521 area code is reserved for special services (Non-Geographic Services). Numbers in it are used for personal communications services in the 5YY non-geographic pool.
How 521 is used
Numbers in 521 are used for personal communications services such as one-number follow-me forwarding. The called party (the subscriber) pays for the call while the calling party is billed at standard long-distance rates. All 5YY codes share the same purpose and pool of central-office assignments.
- Purpose
- Personal communications services
- Assignee
- NANPA on behalf of the FCC
- Dialed as
- 1-521-NXX-XXXX
History
Creation: Area code 521 was placed into service on September 12, 2017 as the eighth 5YY non-geographic NPA, relieving 522. It was reserved in May 2012 (NANPA Planning Letter 703) alongside 523-529 and other codes to augment the dwindling 5YY pool, and was activated as the prior code began to fill.
Relieved: Area code 521 was activated to relieve 522.
Mnemonics: Prior to 1995, the middle digit of area codes was restricted to 0 or 1, which do not correspond to letters on a phone's dialing pad. Because 521 contains 0 or 1, it has no mnemonic letter equivalent.
Sources: en.wikipedia.org/wiki/Personal_communications_service_(NANP), www.nanpa.com/numbering/5xx-nxx-codes.
Other special-use area codes
Same-category codes first, then the rest of the NANP special-use portfolio.
Frequently Asked Questions
What is area code 521 used for?
521 is a special-use area code in the North American Numbering Plan. The 521 area code is reserved for special services (Non-Geographic Services). Numbers in it are used for personal communications services in the 5YY non-geographic pool.
How is 521 dialed?
Numbers in 521 are dialed as a full ten-digit number (1-521-NXX-XXXX). It is a non-geographic area code, so 1-521 numbers are not tied to any city or state.
Who assigns 521 numbers?
NANPA on behalf of the FCC
What did 521 relieve or replace?
Area code 521 was activated to relieve 522 as that pool of numbers neared exhaustion.
When did area code 521 go into service?
Area code 521 was placed into service on September 12, 2017. It was the 8th 5YY non-geographic area code.