Why New Area Codes Appear: Number Exhaustion in Canada

The short answer

A new area code shows up when the existing ones are about to run out of the three-digit prefixes that carriers need to hand out new phone numbers. In Canada, the Canadian Numbering Administrator (CNA) forecasts that date. A public committee then plans "relief", and the CRTC approves it. Under the current Canadian guideline, the answer is always an overlay: a new code covering the same territory, while every existing number stays as it is.

As of October 2026, two new codes are approved and on the calendar. They are 851 for Nova Scotia and Prince Edward Island and 568 for Alberta. A third complex, Eastern Quebec, gets 273 in early 2027. This article explains how the process works, using the planning documents themselves. It is educational, not legal advice. Dates come from the sources cited, read on 28 October 2026, and they can change.

Why area codes run out

Every number in Canada and the rest of the North American Numbering Plan has the format NXX-NXX-XXXX. N is a digit from 2 to 9 and X is any digit ^[1]. The first three digits are the area code, which the industry calls an NPA. The next three are the central office code, or CO code (the "prefix" or "exchange"). The last four are the line number ^[2].

Two details make area codes run out faster than the raw arithmetic suggests:

• Numbers are handed out in large blocks. A CO code holds 10,000 line numbers, and carriers have historically received whole CO codes. The plan's theoretical capacity is 800 area codes x 800 CO codes x 10,000 numbers, or 6.4 billion ^[1]. An area code holds far fewer usable codes than that.
• Prefixes are tied to a place. Each CO code belongs to one rate centre (an "exchange area" in Canada). A prefix assigned to one rate centre cannot be reused in another. When no prefixes are left for assignment, another area code has to be added ^[3]. A province with hundreds of exchange areas and many competing carriers uses up prefixes much faster than its population alone would suggest.

So "exhaustion" does not mean every possible number is in use. It means there are no more CO codes left to assign in that area code complex.

How exhaustion is measured

Canadian carriers file a Numbering Resource Utilization Forecast (NRUF) with the CNA, and the CNA rolls the results up into a Projected Exhaust Date (PED) for each area code complex. The 2026 cycles show the rhythm: January 2026 results were posted on 25 March 2026, and July 2026 results on 24 September 2026 ^[4]. In the US, NANPA publishes its exhaust analysis every April and October and can declare "jeopardy" to ration CO codes when demand outruns the forecast ^[5].

The trigger in Canada is a 36-month window. For each area code projected to exhaust within 36 months, the CRTC announces a Relief Planning Committee. The CNA chairs it, and anyone may take part ^[6].

Forecasts move, sometimes a lot. Here are the exhaust dates for Nova Scotia and PEI (782/902) across four forecasts:

The first three rows come from the NPA 782/902 Planning Document. The last row comes from the CNA NPA Status Report posted 29 September 2026. When the July 2025 forecast pushed exhaust back by 32 months, the committee paused under the guideline's automatic-deferral rule. It restarted when the January 2026 forecast brought the complex back inside the 36-month window ^[7].

Split, overlay or boundary realignment

There are three classic ways to add capacity. The CNAC FAQ and the US federal rule ^[8] describe them the same way:

Sources: CNAC FAQ; eCFR.

The cost of an overlay is dialling. A US overlay cannot start unless ten-digit dialling is mandatory for every call within and between the area codes it covers ^[8]. In the US, state commissions choose the method ^[8].

Why Canada only uses overlays now

Canada settled the question in its planning guideline. Both 2026 planning documents quote it: "The only NPA Relief Method considered in Canada is the Distributed Overlay Method which superimposes or 'overlays' a Relief NPA on top of an entire existing NPA or NPAs." ^[9]. There are three variants:

1. A new code over an area served by a single code.
2. A new code over an area already served by several overlay codes (this is what Nova Scotia/PEI and Alberta are getting).
3. A new code spanning several adjacent area code regions within a province.

Canada did not always work this way. Alberta's history shows both methods. Area code 403 was split in January 1999, and 780 became the northern Alberta code. From 2008 on, every new Alberta code has been a province-wide overlay ^[9].

Case study: Nova Scotia and PEI get 851

• Decision. Telecom Decision CRTC 2026-190, dated 29 July 2026, approved a distributed overlay of new area code 851 over 782/902, starting 27 May 2028 ^[10][11].
• Area. It covers 174 exchange areas, including Halifax, Charlottetown, Sydney, Truro and Summerside ^[11].
• Milestones. Carriers should have 851 active in their networks by 27 February 2028 for testing. Carriers can be assigned 851 CO codes from 27 November 2027, but cannot activate them before the relief date of 27 May 2028 ^[11].
• Dialling. Ten-digit local dialling is already mandatory in 782/902, and "local dialling plans will not change" ^[6].
• How long it lasts. The planning document projects that the 782/851/902 complex will exhaust in Q1 2045 ^[7].
• Background. 782 was overlaid on 902 in 2014 ^[7].

Why 27 May 2028? The guideline recommends a relief date about six months before the projected exhaust date, and carriers avoid summer cutovers ^[7]. If you saw "late 2027" for 851 earlier, it came from the July 2025 proposal (PROC). That document proposed a relief date of 27 November 2027 based on the older June 2028 forecast ^[12]. The approved date replaces it.

Case study: Alberta gets 568

568 will be Alberta's sixth area code:

Source: Alberta Planning Document.

The next code is no longer a draft. Telecom Decision CRTC 2026-252, dated 29 September 2026, approved a distributed overlay of 568 starting 10 June 2028 ^[13][14].

• Area. It covers all 337 exchange areas, including Calgary, Edmonton, Airdrie, Fort McMurray, Grande Prairie, Lethbridge, Medicine Hat and Red Deer.
• Milestones. Network testing starts 10 March 2028. Carriers can be assigned 568 CO codes from 10 December 2027, but cannot activate them before 10 June 2028 ^[14].
• Timing. The January 2026 forecast put exhaust at February 2029. The relief date was set about eight months earlier, avoiding July and August ^[9]. The July 2026 forecast moved exhaust to May 2029 ^[15].
• How long it lasts. Not long. The planning document projects that the six-code complex will exhaust in Q4 2033, based on average historical growth of 74 CO codes a year ^[9].

What else is in the pipeline

The most recent overlays to go live were 942 in Toronto on 26 April 2025 and 257 in British Columbia on 24 May 2025 ^[17].

Number pooling: the other lever

Overlays add supply. Pooling slows demand. With thousands-block pooling, a CO code stays tied to one rate area, but its 10,000 numbers can be shared among several carriers in blocks of 1,000 ^[2]. A small carrier no longer needs a whole prefix in every exchange it serves.

Canada is rolling it out now. The CRTC set the policy in Telecom Regulatory Policy CRTC 2024-26, Implementing thousand-block pooling (5 February 2024), noting that forecasts showed Canada's geographic numbers could run out before 2030, and the CNA's rollout schedule plans these completion dates ^[19]:

• 23 February 2027 for Alberta and Quebec exchanges
• 25 May 2027 for the Atlantic provinces, Manitoba, Saskatchewan, Yukon and the Northwest Territories
• 28 July 2027 for the final phase

Pooling may stretch future forecasts, but it did not stop 851 or 568.

What changes for your business number

• Your number does not change. That is the point of an overlay. Carriers are told to advise customers that local and long-distance calling areas, prices and dialling plans will not change ^[6].
• Dialling does not change either. Ten-digit local dialling is already mandatory in Nova Scotia/PEI and Alberta.
• New lines may get the new code. After the relief date, a new line, a new mobile or a new staff member's number may come from 851 or 568 once older prefixes run out. Area code alone will no longer tell callers whether you are local.
• Your equipment must accept the new code. The plans ask "owners of Customer Premises Equipment" (on-site phone systems, for example), alarm companies and others to update systems before the relief date ^[6].

Checklist before the relief date:

1. Test that your phone system, alarm panel and any call-blocking rules accept calls to and from the new code.
2. Check website forms, CRM fields and booking tools that validate phone numbers by area code.
3. Make sure printed material shows all ten digits.
4. Do not assume a 902 or 403 caller ID means "existing customer" in any routing or screening rules.
5. If a local area code matters for your brand, secure or keep the number you have now. Our area code guide covers how callers react to area codes, and the area code directory lists codes by region.

How to track upcoming relief

• CNAC relief pages. Each active complex has a page with its relief date, the new code, committee minutes and the approved plans. Examples are 782/902 and Alberta.
• CNA NPA Status Report. One spreadsheet lists every Canadian complex with its latest projected exhaust date and whether it is in relief planning ^[20].
• NRUF results. Canadian results have been posted around March and September; NANPA publishes US results in April and October.
• NANPA planning letters. Each one gives the final dates for one new code, such as PL-639 for 851.

For terms like NPA, exchange and porting, see the glossary.

FAQ

Will my area code change? Not under current Canadian practice. The only relief method Canada considers is the distributed overlay, and overlays do not force anyone to change numbers ^[2][9].

Why not just add digits to phone numbers? That is the long-term plan for the whole North American plan, not for one province. Industry bodies have recommended growing numbers from 10 to 12 digits (format NXXX-XNXX-XXXX) when more capacity is needed. As of the 2022 dialling plan, the participating countries had not agreed on an expansion plan ^[1]. An overlay is far less disruptive.

Can I get an 851 or 568 number before the relief date? No. Carriers can be assigned codes in advance, but none can be activated before 27 May 2028 (851) or 10 June 2028 (568) ^[11][14].

Could the dates move? Yes. The committees keep watching the forecasts and can send a revised schedule to the CRTC if exhaust timing changes significantly ^[7].

What happens if numbers run out before relief? The plans include jeopardy measures. CO codes are then assigned only on CRTC staff instruction, and disconnected business landline numbers can be held out of circulation for at most six months in most cases ^[7].

Auto Attendant can port an existing Canadian number, so a business keeping its 902 or 403 number can bring it along when it changes providers.

Sources

1. Canadian Numbering Administrator home page and news, CNAC (news items dated 2025-04-26 to 2026-10-28)
2. NPA Complex 782/902 Relief Planning, CNAC
3. Planning Letter PL-639: NPA 851 to Overlay NPA 782/902, NANPA / CNA, 30 September 2026
4. NPA 782/902 Planning Document, CNAC, approved 29 July 2026
5. NPA 782/902 Relief Implementation Plan, CNAC, approved 29 July 2026
6. NPA 782/902 Proposal for Relief of an Overlay NPA Complex (PROC), CNAC, updated 18 July 2025 (superseded dates)
7. NPA Complex 368/403/587/780/825 Relief Planning, CNAC
8. Planning Letter PL-640: NPA 568 to Overlay NPA 368/403/587/780/825, NANPA / CNA, 30 September 2026
9. NPA 368/403/587/780/825 Planning Document, CNAC, approved 29 September 2026
10. NPA Complex 367/418/581 Relief Planning, CNAC
11. NPA Status Report prepared for CSCN 136, CNA, posted 29 September 2026
12. July 2026 S-NRUF results, CNA, posted 24 September 2026
13. NPA Relief Overview, CNAC
14. Frequently Asked Questions, CNAC
15. Canadian Numbering Plan and Dialling Plan, Version 9.0, CSCN / CNAC, 25 April 2022
16. Thousands-Block Pooling (TBP) Implementation Page, CNAC
17. NPA Relief Planning, NANPA
18. Area Code Frequently Asked Questions, California Public Utilities Commission
19. 47 CFR 52.19 Area code relief, eCFR (read via firecrawl copy, 2026-10-28)
20. Telecom Decision CRTC 2026-190, CRTC, 29 July 2026 (851 overlay on 782/902; read via Internet Archive copy)
21. Telecom Decision CRTC 2026-252, CRTC, 29 September 2026 (568 overlay on 368/403/587/780/825; read via Internet Archive copy)
22. Telecom Regulatory Policy CRTC 2024-26, Implementing thousand-block pooling, CRTC, 5 February 2024 (read via Internet Archive copy)