Assignment of NPA 521 for Non-Geographic Services.
Primary documents
| Letter | Published | Subject |
|---|---|---|
| PL-511 | 2017-09-21 | Assignment of NPA 521 for Non-Geographic Services. |
| PL-505 | 2017-03-24 | Assignment of NPA 521 for Non-Geographic Services |
All documents are official NANPA planning letters (Tier A sources). This page consolidates every letter we have on record for this event; it is updated automatically when new letters are detected, with sensitive changes held for editorial review first.