You can attempt to change your existing 'complex' service with Telstra to a CAT-A or 'simple' service so it can be ported quick and easily, and to avoid the slow, expensive CAT-C process. Note: It is not possible to convert every number from a 100-block to CAT A services, but you can take the numbers you need.
What is a CAT-C or CAT-A service?
Although it is now mostly due to the legacy systems of Australia's largest carriers, the type of service is decided by the carrier and this affects how it can be ported. The Category-A porting system is (relatively) fast and automatic, so phone numbers that are set up as a basic calling service, or an exchange based divert can be ported quickly and easily. In most cases, humans have nothing to do with it!
Is your telco from another era? Category-C services are defined as 'complex' services by providers that are stuck in the last century. They require a slow and expensive triple-handling of the porting information, compulsory delays, and quite often human error. These ports are project managed by people from all providers in the loop over email, and the reasoning in this day and age is not totally clear. ISDN, multiple consecutive numbers delivered to a single line or service, line-hunt or fax duet - these are just a few 'complex services' that would cause the phone number to be rejected if it was ported as CAT-A.
It is not always possible without disruption. Make sure you ask your provider what impact any of these actions might have.
This article is new, and we will attempt to cover more scenarios in the future.
Our primary recommendation: Reducing your service to a single-line service with no complex services is the best way to port as CAT-A. Most providers will tell you if the service can be ported as CAT-A, so be sure to ask.
Remove Complex Services: If you have easily removable complex services like line-hunt or fax duet - just ask for them to be removed. (Note this may reduce your ability to take multiple incoming calls until the number has been ported across)
Splitting a block of numbers: If you have a block of phone numbers, and you want to keep just one or two, then ask your provider to split off the numbers to a separate service (or even better, a separate account completely). This may take some convincing but it is not impossible.
A note about exchange based diverts: It is sometimes possible to have a phone number that was once regarded as a complex service, changed to an 'exchanged based divert' or 'ongoing redirection'. These are normally portable as CAT-A as long as they are not fixed-term (3,6,12 month) and have no intended future disconnection date.
Important: Ensure that your provider is not re-contracting you to a service - make sure to ask what costs are involved and whether there will be any disruption to your service. You should ask the provider if the service can now be ported as CAT-A, and if possible get it in writing as they will sometimes still reject the CAT-A porting request, and their email can be used to dispute the rejection.