When it comes to phone services, one of the biggest concerns for small businesses is about how they can switch their telephone number from one carrier to another, or from traditional PSTN lines to VoIP.

The NBN is bringing massive changes to the way businesses communicate, in particular, the fact that everyone has to take steps to migrate their existing phone services to an NBN (Ready) solution. This article will take a look at what is commonly called ‘number porting’ and give you the information you need to help make switching your existing telephone number to a new service as smooth as possible.

What is Number Porting?

When you decide to move to a new carrier or switch to VoIP, it’s probably important for the continuity of your business to keep your existing phone number. This is called ‘porting’, the process by which your old carrier and new carrier.

Even though the NBN now means that every Australian home and business has to port their phone numbers to a new VoIP service, number porting isn’t a new thing. Whenever you set up a phone service of any kind, with any carrier, a number is either chosen by you (in the case of 1800, 13 and 1300 numbers) or allocated to your business based on your location. Whichever phone service carrier you have chosen, owns the number?

There are two types of number porting, Category A and Category C, and below we will look into what the difference between them is, and how the process works for each.

Category A Number Porting

Category A number porting is when you are moving a single telephone number (usually from a PSTN service) to a new VoIP based system, and is the most simple type of port.

First, your new carrier will submit a porting request to the old carrier who currently holds the phone number you want to port, and it is then your old carrier’s responsibility to accept the port request. This part of the process generally takes 1-3 business days. Once the request has been accepted there will be a cutover period of between 1-2 business days before the port is complete ad the new number can be accessed through your new carrier.

If all goes smoothly, a Category A Number Port will be complete between 4-6 business days.

Important Information about Category A Number Porting

Before a Category A port can be completed, all complex services on the existing lie will need to be removed and the line must remain active. Removing all complex services means that the process can be made as simple as possible and the cost of porting will be minimised, as well as the time it takes to complete.

You are charged a porting fee from the moment your existing (new) carrier submits a porting request to your old carrier, and if the port is rejected and the application has to be submitted again, you will have to pay the fee a second time. The two main reasons a port request may be rejected are because information on the application has been incorrect, such as a wrong address or account number, or because complex services attached to the number have not been removed before the request was submitted.

Category C Number Porting

The process for Category C number porting is more complex because they involve the transferring of blocks of numbers that are already VoIP based. If your business has more than one direct telephone number, a Category C port will be how you migrate to a new carrier. This is a much more complex process than a simple Category A transfer, and will take longer to complete.

First, you new carrier will submit a porting request and just like with a simple port, your old carrier will have to accept the porting request. For Category C ports, this process can take around 10 business days to complete in a best-case scenario, but it often takes longer. After the port has been accepted your new carrier will be in contact with you and your old carrier to arrange a date for cutover. It is difficult to give a specific timeframe for this part of the process, because it differs with each carrier and with each business. Once the date is set, you must also allow for a 10 day grace period. The cutover itself should occur entirely on the date itself, and there is a 4 hour window for an emergency return should the porting process fail on that day.

A Category C Number Port will usually take between 4-6 weeks to complete. The timeframe depends on the complexity of the port and how accurate information is on the first request application.

Important Information about Category C Number Porting

Making sure that all information is correct on your first port request application is important in keeping time and expense to a minimum. While a Category C port can have more than one account number, the customer name and address must be the same at both ends for the request to be accepted.

Another important thing to note is that all numbers must be ported, even if only one number is actually needed, and the only way to get around this is to disassociate all numbers before you submit your port request.


This article has given you some detailed information about what number porting is and how the process works when you’re switching your business phone service to a new provider or a new NBN service.

The best advice we can offer is that you give our team at SpringCom a call to talk about your unique circumstances and how you can keep your phone numbers to ensure continuity of business when you migrate your services. Without any pressure or obligation, we’ll offer you genuine advice to help make sure you’ve got all the information you need to make the switch as smooth as it can be for your business. Call us today on 1300 857 194.