VoIP • SA dialling

Why you dial 0 first in South Africa, and why it breaks your CRM if you store it

The leading 0 is a national habit most South Africans never question. For a business running VoIP, a CRM or an auto-dialler, getting it wrong silently misroutes calls. Here is what the 0 actually does and how to store numbers so they always connect.

Last verified 02 June 2026
By the WhichVoIP editorial team
7 min read

0national trunk prefix

+27country code that replaces it abroad

9 digitsthe number without the trunk 0

E.164the format your systems should store

The short answer

Why do you dial 0 before a phone number in South Africa?

The leading 0 is a trunk prefix. It tells the network the call is national rather than local or international. You drop it when dialling South Africa from abroad and replace it with the country code +27. Inside a VoIP system or CRM, store numbers in international E.164 format so they route correctly every time.

country code (shown as +27)

national digits after the 0

max digits in an E.164 number

ICASA Numbering Plan Regulations

Person Dialling A South African Phone Number On A Smartphone Keypad — The 0 you dial every day is a routing instruction, not part of the number. That distinction matters the moment a computer stores it.

What the 0 actually does

South Africa uses a closed numbering plan, administered by ICASA under the Numbering Plan Regulations of 2016. You always dial the full number, and the leading 0 signals a national call.

The 0 is called a trunk prefix. When you dial it from inside the country, the network reads it as “route this call nationally” and uses the next digits to decide where. The real, internationally unique part of the number is the nine digits that follow the 0.

How the main South African prefixes break down

Number type	Example prefix	Typical use
Geographic	021, 011, 031	Landlines tied to a region
Mobile	06x, 07x, 08x	Cellphones across all networks
Non-geographic	087	VoIP and hosted PBX numbers
Toll-free	0800	Caller pays nothing; business absorbs the cost
Shared-cost	0860 / 0861	National business lines (split or flat-rate)

✓

Bottom line: an 087 number is not tied to a city. That is exactly why it suits a VoIP business with remote staff or several branches, the number follows the system, not the building.

Calling South Africa from abroad

This is where the 0 trips people up. Internationally, you drop the trunk 0 and use +27 instead.

A Cape Town landline written locally as 021 123 4567 becomes +27 21 123 4567 from overseas. The +27 replaces the 0; you never dial both. Dialling +27 0 21 keeps the call from connecting.

The same number, two ways of writing it

Why this matters for VoIP, CRMs and auto-diallers

A leading 0 stored in a database is the quiet cause of failed click-to-dial, mismatched caller ID and broken integrations.

Modern phone systems route on the full international number. If half your contacts are saved as 082… and the other half as +2782…, your click-to-dial, deduplication and reporting all drift. The fix is a single house rule.

Watch out: WhatsApp, most CRMs and SIP platforms expect E.164. A number saved with a local 0 instead of +27 can silently fail to match an existing contact or fail to connect at all.

Three rules that keep numbers connecting

Store everything in E.164Save the international form (+27…) in your CRM and phone system, regardless of how staff type it.

Let the system add or strip the 0Use the platform’s number-translation rules to show the friendly local 0 to users while routing on +27 underneath.

Test both formats on importBefore a bulk contact import or an auto-dialler campaign, test that numbers entered with and without the 0 both resolve.

Scenario	With the 0	Stored as E.164 (+27)
Dialling inside SA	Connects	Connects (system adds 0)
Dialling from abroad	Fails	Connects
CRM contact matching	Inconsistent	Reliable
WhatsApp / SIP routing	Often rejected	Accepted

The 0 is a dialling instruction, not part of the number. Treat it that way in your systems and calls just connect.

WhichVoIP editorial view

Close-Up Of A Desk Phone Keypad Lit Warmly — Show staff the familiar 0; store the +27 underneath. Number-translation rules let you have both.

Our verdict

The leading 0 is harmless when you dial by hand and quietly destructive when a computer stores it. The whole problem disappears with one convention: keep the international E.164 number in your databases and let the phone system present the local 0 to humans.

Our recommendation: set an E.164 storage standard across your CRM and phone system today, then spot-check a handful of contacts to confirm both local and international dialling resolve.

Setting up VoIP for your business?

Compare South African VoIP and hosted PBX providers and get quotes that include number setup and porting.

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SA phone numbers guide

Frequently asked questions

Do I dial 0 when calling South Africa from another country?

No. From abroad you drop the leading 0 and dial the country code +27 followed by the nine-digit number. So 011 123 4567 becomes +27 11 123 4567. You never dial both the +27 and the 0.

What is E.164 format?

E.164 is the international standard for phone numbers: a plus sign, the country code and the national number, up to 15 digits in total. For South Africa that is +27 followed by the nine-digit number, with no leading 0. It is the format VoIP systems, CRMs and WhatsApp expect.

What does the 0 in front of South African numbers mean?

It is a trunk prefix. When you dial it inside South Africa, it signals that the call is national and tells the network to route it using the digits that follow. It is not part of the number’s internationally unique identity.

Why are some of my CRM click-to-dial calls failing?

A common cause is inconsistent number storage. If some contacts are saved with a local leading 0 and others in +27 format, the system cannot match or route them reliably. Standardise on E.164 and use the platform’s translation rules to handle the local 0.

What is an 087 number?

087 is South Africa’s non-geographic VoIP number range. It is not tied to a city or region, which makes it well suited to businesses with hosted PBX systems, remote teams or multiple offices that want one number regardless of location.

Keep reading

South African phone numbers: a business buyer’s guide
Number porting in South Africa: keep your number on VoIP

Sources: ICASA Numbering Plan Regulations (2016) and the ICASA numbering pages; ITU-T E.164 international numbering standard. Verified 02 June 2026.