Which number format should my PBX use?

What is E.164?

E.164 is the international standard for writing phone numbers. A number starts with its country code and leaves out any leading 0. For example, the Sydney number 02 5550 1234 becomes 61255501234. With a plus in front, as +61255501234, it's called +E.164. It's the format Cloud SIP uses everywhere.

A number in +E.164 is the same number from anywhere in the world, so no system has to guess which number you mean. That's why we recommend it for everything your PBX sends.

What format should my PBX send for the number dialed?

Send +E.164 if you can. Cloud SIP accepts three formats, and converts the other two to +E.164 before the call goes to the phone network:

• +E.164, such as +61255501234. Recommended.
• E.164 without the plus, such as 61255501234. Apart from 13, 1300, and 1800 numbers, Cloud SIP reads digits that don't start with a 0 as an international number, country code first.
• Australian national format, such as 0255501234. Cloud SIP converts it using Australia as your home country.

This table shows what Cloud SIP does with the numbers that PBXs most often send. Every Australian example is a number set aside for use in examples, so none of them rings anyone.

When Cloud SIP can't read a number, the call fails with 484 Address Incomplete. The Console shows the error "Could not parse" followed by the number. For every cause, see SIP 484 Address Incomplete.

How do I dial 13, 1300, and 1800 numbers?

Keep every digit, including the leading 1. Unlike a landline or mobile number, a 13, 1300, or 1800 number has no 0 to drop. In E.164, it's +61 followed by the whole number:

• 1300 975 707 becomes +611300975707.
• 1800 975 707 becomes +611800975707.
• A six-digit 13 number, 13 xx xx, becomes +6113xxxx.

Sending them exactly as dialed, such as 1300975707, also works. Problems start when a PBX rule built for landlines strips the first digit and adds +61. That rule turns 1300975707 into +61300975707. Give 13, 1300, and 1800 numbers their own rule that strips nothing, or send every number as dialed.

How do I call New Zealand and other countries?

Dial the country code without the 0011 international prefix. People dial 0011 for international calls from Australian phones, but it isn't part of the number. Cloud SIP refuses numbers that start with it. For example:

• An Auckland number, 0011 64 9 xxx xxxx, is sent as +649xxxxxxx.
• A New Zealand mobile, 0011 64 21 xxx xxxx, is sent as +6421xxxxxxx.

If your users dial 0011 out of habit, add a PBX rule that strips those four digits and adds +. The Teams Direct Routing dial plan in our docs already does this.

Toll fraud prevention can also block calls to some countries. For more information, see what to do about toll fraud.

How do I dial emergency services?

In Australia, Cloud SIP routes calls to 000 to emergency services. Your PBX can send the number as 000 or +61000, with one of your Enfonica Australian numbers as the caller ID.

Emergency services are given the address on that number's regulatory listing. Make sure that each phone presents its own number, and that each number's listing has the right address.

What format should my caller ID be?

Use +E.164 for the caller ID too, for example +61255501234. It must be a complete phone number that you hold. Australian national format, such as 0255501234, is also accepted.

Cloud SIP refuses a caller ID that it can't read as a number with 484 Address Incomplete, and the Console shows "Could not parse CLI". Caller IDs it can't read include:

• A number missing its area code, such as 255501234
• An extension number
• A username

The word "anonymous" is the exception. When your PBX sends it, Cloud SIP presents one of your project's numbers instead and keeps the call private.

You can't use 1300 and 1800 numbers as a caller ID at all. For private calls and other caller ID problems, see Caller ID problems.

What format do incoming calls arrive in?

Cloud SIP sends incoming calls to your PBX with the number that was called in +E.164, such as +61255501234. The caller's number is in +E.164 too. A caller who withholds their number arrives as anonymous.

Your PBX's DIDs (direct inward dialing numbers) or inbound routes must match the called number exactly, plus sign included. If yours can't accept the plus, you can use a to header to set the number that Cloud SIP sends for each phone number. To learn how, see Connect your PBX to Cloud SIP. To change the format for many numbers at once, contact support.

Why does calling back a missed call fail?

The PBX has dropped part of the caller's number before you call it back. A missed call from +61491570156 that's redialed as 491570156 has lost its plus and its country code. Cloud SIP reads it as a number in another country.

Check how your PBX stores and redials incoming numbers. Make sure that its outbound rules accept numbers that start with +. In 3CX, an outbound rule with the prefix 0-9,+ matches numbers that start with a digit or with +.