NumberResearchArea code 626 is on NANPA's relief-planning list. Here's what the numbers show.
Prepared by the NumberResearch.org Data Desk · Reviewed and approved by the Publisher
Area code 626 — the San Gabriel Valley's area code since it was split from 818 in June 1997 — appears on NANPA's current relief-planning list, the procedural step that precedes an overlay or other relief measure. No planning letter has been issued yet for this cycle. This note lays out what the public assignment records show, and what typically happens next.
Where 626 stands
As of the NANPA CO-code file dated 09/18/2026, 748 of roughly 792 assignable prefixes (NXX codes) in 626 are assigned — about 94.4%. The first assignment on record dates to 2001; the most recent was made in August 2026.
Assignment pace over the past eight years:
| Year | New prefixes assigned |
|---|---|
| 2019 | 12 |
| 2020 | 17 |
| 2021 | 26 |
| 2022 | 18 |
| 2023 | 17 |
| 2024 | 24 |
| 2025 | 9 |
| 2026 (through Sept) | 4 |
Sixteen prefixes were assigned in the last 24 months. NANPA's Available-codes report lists 52 prefixes still open for assignment in 626 — at the recent pace they would last several more years. But prefix arithmetic is not the whole story, and the thousands-block layer below shows why. NANPA's exhaust models weigh pooling behavior, carrier forecasts and block-level demand, and NANPA — not this publication — decides when relief planning begins. It has begun.
The layer where demand actually shows: thousands-blocks
Under number pooling, carriers in 626 mostly do not take whole prefixes — they take individual 1,000-number blocks (626-NXX-XXXX) inside prefixes that are already assigned. That is where the real 2026 activity is:
- New full-prefix assignments in 2026: 4
- New thousands-block assignments in 2026: 89 (after 304 in 2024 and 96 in 2025; the most recent on 09/17/2026)
- Blocks currently listed as available in the 626 pooling pool: 44
Read those last two numbers together: at 2026's assignment pace, the blocks now sitting in the shared pool cover only a few months of demand. The pool is replenished — opening a new prefix adds up to ten fresh blocks, and carriers return blocks they no longer need — so this is not a countdown clock. But a thin pool is exactly the pressure signal that pushes rate centers to open new prefixes, drains the 52 remaining codes, and keeps 626 on the relief-planning list.
Two caveats worth stating plainly. First, prefix-level assignment does not equal number-level exhaustion; thousands-block pooling stretches capacity within assigned codes. Second, these are initial-assignee records: because of number portability, they do not say who serves any individual number today.
The neighborhood precedent
626 is not alone. Two other Southern California codes on the same relief-planning list show what the end game looks like:
- 714 (Orange County, in service since 1951) now has 800 prefixes assigned — every NXX in the code, including values our ~792 denominator treats as unassignable. It is, for practical purposes, full.
- 657, the overlay added on top of 714's geography in 2008, has itself reached 708 assigned prefixes — which is why the 714/657 complex is back on the relief list just 18 years later.
The 714/657 history is the most likely template for 626: an overlay, meaning a second area code layered over the same geography. Existing 626 numbers would not change; ten-digit dialing is already the rule.
What happens next, and when we'll know
The formal sequence is: NANPA relief planning → industry meetings → a filing with the California Public Utilities Commission → a NANPA planning letter announcing the decision, with permissive and mandatory dialing dates. We check NANPA's planning-letter feed twice daily and will publish the letter's details the day it appears — follow the relief tracker, and the current state of the code is always at numberresearch.org/area-code/626.
Update, 09/18/2026: this analysis now includes the thousands-block layer and the official Available-codes count. Our original text estimated "~44 remaining assignable codes" from the ~792 denominator; NANPA's Available report lists 52. We publish corrections rather than silently rewriting — see our methodology.
Sources: NANPA NPA database, CO-code assignment file, Thousands-Block Assignment report and Available-codes report (file dates 09/17–09/18/2026, Tier A primary sources); NANPA planning letter PL-028 (1997 creation of 626 from the 818 split). Figures are computed from the source files and recalculated on every import; see methodology. Relief-planning designations are NANPA's; the projections above are simple arithmetic from public assignment records, not an official exhaust forecast.