LincMad’s New Area Code Dates

Last updated

Older splits and overlays (effective before ) — see oldnews.html;
Note: all dates are in year-month-day format, so = May 24, 2025.
Dates given in the form are 3rd Quarter of 2029, for example.
The first date listed is for mandatory 10-digit (or in some cases, 1+10-digit) local calls; if no date is given, the area already has mandatory 10D/1+10D local calls. The second date is when numbers in the new overlay code can be assigned.

Old New Area Affected 10D/1+10D Dialing Overlay Test Number
516 363 NY: Nassau County (western Long Island); (516 & 363 overlay) 363-990-TEST
707 369 CA: north coast of California, Santa Rosa, Napa, Eureka 369-369-1369
309 861 IL: Bloomington, Peoria, Quad Cities 861-861-0861
561 728 FL: Palm Beach County 728-728-1728
845 329 NY: Poughkeepsie, north suburbs of NYC (except Westchester County) 329-990-TEST
513 283 OH: Cincinnati; (Reinstated; back in 2001, 283 was announced as the new overlay code, but then, in 2002, 283 was assigned as a prefix in 513 (i.e., numbers of the form 513-283-xxxx), which usually would mean that 283 would not be used as an overlay, due to the obvious potential for confusion. However, the PUCO announced that 283 will be the overlay, effective ) 283-283-0283
506 428 🇨🇦 NB: entire province of New Brunswick, Canada •
l’ensemble de la province du Nouveau-Brunswick

1–428 + (580, 610, or/ou 999) + –TEST(–8378) or/ou –BILL$(–2455)$
920 274 WI: Green Bay, northeastern; (originally scheduled for 2012, finally scheduled for , but now advanced by 9½ months)

633 🇨🇦 Canada: non-geographic numbering (includes caller-pays cellular and machine-to-machine) (none)
867 🇨🇦 Northwest Territories: Yellowknife local calling area only changed to mandatory 10-digit local calls; (note: Yukon, Nunavut, and the rest of NWT get to keep 7-digit local calls) (n/a) (not applicable)
807 🇨🇦 ON: westernmost part, from Lake Superior (Thunder Bay) to Hudson Bay (Fort Severn/‌ᐗᔕᐦᐅ ᐃᓂᓂᐗᐠ); 807 changed to mandatory 10-digit local calls for absolutely no valid reason; see Why is Thunder Bay losing 7-digit local calls?
(Note: Thunder Bay itself got a reprieve until .)

(T-Bay only)
(n/a) (not applicable)
227 MD: Silver Spring, suburbs of Washington, D.C. 227-990-TEST
382 🇨🇦 ON: London, Windsor 382-610-TEST
618 730 IL: East St. Louis, southern 730-730-1730
645 FL: Miami/Dade, Florida Keys 645-645-1645
AZ: Phoenix metro area; the boundaries from the 602/480/623 split were erased, creating the 602 & 480 & 623 overlay; in practice, mostly new 623 numbers will be assigned into the current 480 and 602 areas; the 480‡ area already had mandatory 10D local calls due to The Big 10D (none)
608 353 WI: Madison, southwestern 353-353-1353
816 975 MO: Kansas City; (suspended in 2002, finally resurrected in 2021, took effect in 2023) 975-975-1975
716 624 NY: Buffalo, western tip 624-624-1624
804 686 VA: Richmond, Petersburg; 804 & 686 overlay 686-990-TEST
709 879 🇨🇦 NL: entire province of Newfoundland & Labrador, Canada (was postponed indefinitely, but finally happened)l’ensemble de la province de Terre-Neuve-et-Labrador, Canada (était remis indéfiniment, mais désormais c’est arrivé); (mandatory 10-digit local dialing began • la composition obligatoire de 10 chiffres pour les appels locaux commença le )

1–879 + (610, 630, or/ou 640) + (–TEST/–8378 or/ou –BILL$/–2455$)
870 327 AR: Jonesboro, Pine Bluff, southern, eastern, north central (surrounds Little Rock on 3 sides). After postponing and then advancing the date, the 870 & 327 overlay finally took effect on note: Arkansas is also planning to implement a “boundary elimination” overlay on the entire state in 2027; see the note below for more information.

904 324 FL: Jacksonville 324-324-0324
440 436 OH: Lorain, Ashtabula 436-436-1436
573 235 MO: Columbia, Jefferson City, Cape Girardeau, eastern Missouri outside the St. Louis metro area 235-235-1235
864 (821) SC: Greenville, Spartanburg, northwestern; note: area code 864 is not affected by “The Big 10D” and will keep 7-digit local calls until a month before the overlay 821-821-0821
507 (924) MN: Rochester, Mankato, southern 924-924-1924
(738) CA: Downtown Los Angeles (the split boundary between 213 & 323 was erased on , creating the 213 & 323 overlay; 738 will be added as an additional overlay in late 2024) 738-738-1738
(532) non-geographic: more numbers for iPads, tablets, etc. — mostly non-dialable from ordinary phones; (implementation date not yet announced; the new code was expected in late 2023 or early 2024, but significant numbering resources have been reclaimed, pushing out the effective date by several months) (none)
621 TX: Houston area 713 & 281 & 832 & 346 overlay will add 621, in early 2025 621-621-1621
530 (837) CA: Redding, Chico, Davis, Lassen, northeastern 837-837-1837
423 (729) TN: Chattanooga, Johnson City, not Knoxville; 729 overlay expected in early 2025. Area code 423 will retain 7-digit local calls until shortly before the overlay takes effect 729-729-0729
559 (357) CA: Fresno; (Note: area code 559 still has 7-digit local calls. Permissive 1+10-digit dialing will officially begin .) 357-357-1357
(942) 🇨🇦 ON: Toronto (only • seulement) 1–942–610 + (–TEST/–8378 or/ou –BILL$/–2455$)
(257) 🇨🇦 BC: British Columbia, entire province • l’ensemble de la province de la Colombie-Britannique 1–257 + (580, 610, 710, 810, or/ou 999) + (–TEST/–8378 or/ou –BILL$/–2455$)
206 (564) WA: Seattle; 360 & 564 overlay will expand to include 206, and will later expand to include 425 and 253 (none)
970 (748) CO: Grand Junction, northern and western Colorado, officially scheduled 748-748-1748
318 (457) LA: Shreveport, Alexandria, Monroe, northern 457-457-1457
(679) MI: Detroit, Ann Arbor; (officially scheduled); 679 will overlay 313 on , and expand to also overlay 734, circa 2026. Neither 313 nor 734 is affected by “The Big 10D.” 679-679-0679
334 (483) AL: Montgomery, southeast; implementation details to be determined 483-483-1483
AR: entire state; the 870 & 327 overlay will expand to cover the entire state in a “boundary elimination” overlay, currently planned for some time in

Area code 501 (Little Rock) already has 10D local calls as a result of “The Big 10D” and area codes 870 & 327 will have 10D as a result of the initial overlay, so only 479 (northwest Arkansas) will have to change to 10D in 2027.
207 (tba) ME: entire state of Maine; overlay was projected for 2023 or 2024, but has been pushed back to about . My best guess for the new area code is 258. t.b.a.
How to read the chart

black - new area code is already in use
blue - mandatory 10D (or 1+10D) dialing is in effect in preparation for an overlay
green - new area code not yet in use
red - special notations
t.b.a. - to be announced à communiquerse anunciará
t.b.d. - to be determined à déterminerse determinará
- area affected by “The Big 10D”; mandatory 10D began no earlier than , no later than , generally at each carrier’s discretion except where a different date is listed here
$ - test number known to bill

10D/1+10D” refers to the date on which it becomes mandatory to dial all local calls with the area code. In some areas, you must dial only the area code and number, for a total of 10 digits. In other areas, you must dial 1 plus the area code and number on all calls. In yet other areas, you may optionally dial 10D or 1+10D on some or all local calls, or for calls within your own area code overlay whether the call is local or toll. If no date is listed in this column, the area already has mandatory 10D/1+10D local calls, or the listing is for a non-geographic code (such as toll-free numbers) in which there are no local calls, as such.

Overlay” refers to the date on which the new code goes into effect; that is, the first date on which numbers in the new code may be assigned and used.

New area codes indicated with a question mark are speculation, based on available industry data. However, the information should not be considered reliable until it is officially confirmed by NANPA.

The Test Number is a special number (usually, though not always, not charged) that allows you to test whether all the links in the chain from you to a new area code are operating correctly. In order for you to reach a new area code, your premises equipment (office PBX, for example) must allow you to dial it. Then the telco central office must accept the new area code as valid and route it correctly. If the new area code is outside your LATA, your chosen long-distance carrier must also route the call correctly. Calling one of these numbers will usually reach a simple recording saying something like, “You have successfully completed a call to area code XXX.” Note that some test numbers are billable numbers, possibly at international rates. However, most test numbers in the U.S. will not bill. In cases where a test number is shown ending with –TEST, dial –8378 (no charge); for –BILL, dial –2455 (billed).

Note that the test number for a new area code is usually disconnected within a few months after the mandatory date. If you dial one of the older test numbers shown here, you may reach an ordinary subscriber.

Don’t see a split listed here that used to be? Splits and overlays that have been cancelled or indefinitely postponed may no longer be shown.

Notes about specific areas

In early 2021, several area codes that were not expected to run out of numbers until 2024 or later, found themselves with revised projections indicating they need overlays Real Soon Now. The most stark of these is Illinois’ area code 708 (see below).


In Arizona, the 602 area code for Phoenix underwent a 3-way split in 1999, creating the 480 and 623 area codes for the east and west sides, respectively. However, the 480 area code was running out of numbers, with 602 not far behind, while 623 had enough numbers to last for several decades. Thus, the Arizona PUC decided to do a first-of-its-kind double boundary elimination overlay. Because 623 has by far the most unused numbers, there will be many 623 numbers assigned to areas now in 480 and 602, but few if any 480 or 602 numbers will be assigned outside their current boundaries.

Arkansas (new info for 2027)

Area code 870, which covers most of the land area of the state of Arkansas, was scheduled to have an overlay on , but number conservation measures extended its life by several years, so the overlay was postponed indefinitely. The effective date was finally announced: . Of course, 7 months later, the date was advanced by 3½ months; the overlay actually went into effect on .

However, Arkansas is already planning the next area code change: a “boundary elimination” overlay, erasing the boundaries between area codes 501, 479, and 870 & 327, creating one big statewide overlay with (initially) four area codes, in 2027. Implementation details have not yet been determined. Area code 501 already has 10-digit local calls because of the 988 mandate, and 870 switched to 10D in preparation for the first overlay, but 479 will have to introduce 10D for the big overlay. (Early reports suggested 2025, but that is when the network preparation will begin. The actual boundary elimination overlay is planned for 2027.)


In southern California, two old area code splits were erased in a maneuver known as a “boundary elimination overlay”. In San Diego, the boundary between 619 and 858 was eliminated. In downtown Los Angeles, the boundary between 213 and 323 was eliminated. (In each case, the two existing area codes became an overlay, with numbers from either code assignable anywhere in the combined geographic territory.) In late 2024, area code 738 will be added as an overlay on 213 & 323.


The state of Missouri approved overlays for area codes 314 and 816, originally scheduled for 2001, then postponed until 2002, then suspended indefinitely. On , the effective dates were finally announced for 2022 and 2023, although the date for 816 was then pushed back by 8 months. Both the 314 & 557 and the 816 & 975 overlays are now in effect. The overlay for area code 573 has also been officially announced: area code 235 will be added on .

🇨🇦 Canada (English)

The Canadian province of Newfoundland and Labrador was scheduled to have an overlay of new area code 879 on existing area code 709, in but evolving conditions led the CRTC to postpone the overlay repeatedly, and finally postpone it indefinitely. However, the zombie overlay was revived, and officially took effect Thus, the only parts of Canada that do not have overlays are area code 867 (Yukon, Nunavut, and Northwest Territories) and area code 807 (northwest Ontario, including Thunder Bay.)

Note that area code 807 was forced to change to 10-digit local calls, for absolutely no valid reason, but, except for the Yellowknife local calling area, area code 867 gets to keep 7-digit calls.

🇨🇦 Canada (français)

La province de Terre-Neuve-et-Labrador devait mettre en œuvre un recouvrement de l’indicatif 709 avec le nouvel indicatif 879, en mais en raison des conditions évolutives le CRTC a remis plusieurs fois le recouvrement, et enfin le remit indéfiniment. Cependant, le recouvrement mort-vivant est arrivé le Désormais, le Canada recouvre tous les indicatifs sauf le 867 (le Yukon, les T.N.O., et le Nunavut) et le 807 (le nord-ouest de l’Ontario, y compris Thunder Bay).

Noter que l’indicatif 807 passa aux appels à 10 chiffres, sans aucune raison valable, mais, à l’exception de la zone locale de Yellowknife, au 867 on conserve les appels à 7 chiffres.

Time Zone information is now available on the “Locator” page, which lists all active and upcoming area codes in numeric order with major cities.