One of the 86 original 1947 North American area codes, 504 originally covered all of Louisiana and now serves the core New Orleans metro after successive splits.
The essentialsNumbering data · NumberResearch · as of 2026-09-18
Place
New Orleans
Type
geographic
Status
in service
In service since
1947
Projected exhaust
2061 Q3
Status, dates and counts are read from NumberResearch (NANPA / CNAC / FCC records). Assignment records show initial assignees, not the carrier serving a number today.
A · Where it is
Where 504 is
New Orleans metropolitan core: Orleans, St. Bernard and Plaquemines parishes and most of Jefferson Parish..
Communities served wholly or partly by 504:
New OrleansMetairieKennerChalmetteGretna
Lower Plaquemines communities returned to 504 in 2007-2008 after Hurricane Katrina.
B · Relationships
How it relates to other codes
The codes 504 was split from, spawned, or shares its area with. A split divides the map and changes some numbers; an overlay shares the same ground and changes none — what's the difference?
Spawned · 1957318ShreveportIn 1957 most of Louisiana west of the Mississippi River was split off from 504 as area code 318.
Spawned · 1998225Baton RougeWestern portion including Baton Rouge renumbered to 225 on Aug 17, 1998.
Spawned · 2001985Houma / HammondMuch of southeastern Louisiana split off as 985 in 2001.
What's changing. Single area code; no overlay reported.
C · History
How 504 got here
1947
Assigned as one of the 86 original NANP area codes, serving all of Louisiana.
Source: Wikipedia
1957
Most of the state west of the Mississippi River reassigned to new area code 318.
Source: Wikipedia
1998
Baton Rouge area split off as area code 225.
Source: Wikipedia
2001
Southeastern Louisiana split off as area code 985.
Source: Wikipedia
2008-05-01
Mandatory 504-only dialing began for lower Plaquemines communities returned to 504 after Katrina (985 article gives July 1, 2008 — discrepancy).
Source: Wikipedia
D · Capacity
How full it is
Prefixes assigned
583
Prefixes available
217
Thousands-blocks assigned
2,520
Prefix-assignment counts describe allocation to carriers, not how many individual numbers are in use. Full technical records: NumberResearch ↗.
Live status, dates, assignment counts and exhaust forecast — data as of 2026-09-18 (CC BY 4.0).
Place, relationships and history above are compiled by North American Numbers from the sources listed and last checked 2026-09-18. A check date is not an expert review — see how this is made. Flag an error.
North American Numbers