LNP Overview

Local Number Portability in Australia.

Local Number Porting

In 1997, the Australian Communications and Media Authority (ACMA) introduced Local Number Portability (LNP). This framework enables customers to port local and geographic numbers between Carriage Service Providers (CSPs). The policy was aimed at simplifying the process of switching and increasing competition among carriers. This decision allowed customers to retain their existing phone numbers when transitioning from one carrier to another, streamlining telecommunications transitions.

LNP was initially established by Comms Alliance in 1999 under ACIF C540. However, many acronyms associated with the process pose challenges when navigating this framework.

LNP is divided into two distinct processes: Simple Ports, known as Cat A, and Complex Ports, known as Cat C. Cat A ports involve transferring a single number from one carrier to another, while Cat C ports refer to more complex ports that require project managers from both the losing and gaining carriers to oversee and regulate. The majority of porting requests fall into the Cat C category.

Simple Number Porting (Cat A)

Cat A ports involve the seamless transfer of single numbers, such as copper PSTN/POTS lines, between carriers through an automated process. These transfers typically take a few days to a week, with customers receiving notifications upon completion. Carriers on both ends have automated switches that facilitate the port and correctly route the number.

For a service to qualify for Cat A porting, it must be eligible and submitted as such by the gaining carrier, obligating the losing carrier to follow the Cat A process. If a port meets Cat A criteria, it cannot be rejected by the losing carrier as invalid and resubmitted as Cat C, except in cases where multiple single numbers are being transferred, as Cat C can be more cost-effective.

If a port fails, customers can request a reversal, returning the service to the losing carrier and terminating the port's process. If the customer still wants to port the number, a new order must be initiated.

In some cases, Cat A ports can involve three carriers when the donor carrier and the losing carrier are different entities. This scenario extends the porting duration by a few additional days.

Complex Number Porting (Cat C)

Cat C ports encompass all number transfer cases not meeting Cat A requirements and may include cases where a Cat A port is shifted to Cat C when necessary. These ports demand coordination between project managers from both gaining and losing carriers, involving defining porting details and executing transfers through their internal processes.

Cat C ports have longer lead times, potentially taking up to 90 days from submission, and can be processed after hours unlike Cat A ports. They involve manual management and necessitate project managers from both carriers to liaise, confirming number portability and agreeing on suitable transfer time frames.

The LNP code doesn't restrict industry participants from setting different arrangements, but it establishes the minimum standards carriers must meet. This means the losing carrier isn't obliged to optimize their porting out process or inform the gaining carrier when the port is successfully completed, distinguishing Cat C ports from the automated nature of Cat A transfers.

Porting Number Validation

Porting Number Validation (PNV) is a process used in the telecommunications industry to verify the validity of a request to port a phone number from one service provider to another within Australia. This process is essential to ensure that the porting of phone numbers is done accurately and securely.

PNVs are used when either a single number, or a group of multiple numbers are lodged within a single Cat C porting request, this approach helps avoid the necessity of resubmitting to CNA, as it allows potential errors to be identified in the PNV before the CNA submission. However, PNVs do not guarantee a physical audit of the services but rather an assessment of available electronic data by the losing carrier.

The validity of the PNV is limited to the date of issue, recognising that services can change status between a successful PNV and a rejected porting request. Hence, PNV requests should be processed within 5 business days.

Once a PNV request is submitted and goes through the evaluation process, Response and Rejection Codes play a crucial role in conveying the outcome and reasons behind the decision. These codes serve as a standardised means of communication between the gaining and the losing carrier, as well as regulatory authorities when applicable.

The procedures and requirements for handling a response or rejection code can vary, and they are often dependent on the policies and practices of telecommunications service providers and regulatory authorities in Australia. To address the particular rejection code and continue with the porting process, refer to the documentation provided by the relevant carriers and authorities. If needed, contact their customer support for guidance on resolving the billing-related issues.

Response Codes

Response codes are used to communicate the status of a porting request and if the porting process can proceed. Response codes may also provide additional information about the expected completion date, any further steps required, or other relevant details.  

With the exception of the "R" response code, which carries its specific implications, all other response codes are considered portable. To ensure that we proceed correctly, our guidance is primarily based on the information contained within the "reject/comment" and "Address" columns. These columns play a crucial role in helping us navigate the porting process effectively, allowing for a more streamlined and precise response to various codes.

Table 1: Response codes and classifications for PNV requests

P: Prime/Directory Service Number

A "prime" or "directory service" number refers to numbers that are listed in public directories or phone books and may be associated with businesses or government organisations. These numbers are typically publicly available and easily accessible to the public. They are often used for directory assistance and information services.

A: Associated Service Numbers

The Associated Service Number code indicates that there are other phone numbers or services linked to the number. Alternatively, the numbers may be associated with a complex service (such as ISDN or PRI) or are being ported to a new carrier at the same time.  

S: Standalone Number

The term "standalone number" response code is used to classify a porting request where a phone number is not associated with any other services or accounts. It's a straightforward transfer of the phone number from one carrier to another, without any complexities or additional services to consider. This code typically signifies that the porting process for that specific number can proceed smoothly and with few potential issues.

R: Reserved Number

A "reserved number" response code may signify that the phone number is unable to be ported because it is reserved for a particular use, such as a special service, emergency service, or other specific circumstances. In such cases, the porting process may not be allowed for that number until the reservation or restriction is lifted.

D: Exchange Based Diversion/Prepaid Redirection  

The term "exchange-based diversion or prepaid redirection" response code suggests that the porting request may involve special conditions related to the handling of the number. The phone number in question may be subject to exchange-based diversion or prepaid redirection services.  

Exchange-based diversion typically refers to a feature where calls to the ported number are automatically redirected to a different number or service, often as part of a business continuity plan or during a transition period. Prepaid redirection may indicate that the number has prepaid services associated with it, and may need to be addressed during the porting process.

SS: Secondary Service Linked to this Number

The "secondary service linked to this number" code suggests that there are additional services or features associated with the phone number that is being ported. The secondary services linked to a phone number can vary but often include features like call forwarding, voicemail, call waiting, or other value-added services provided by the current telecommunications service provider. When a phone number has secondary services attached to it, the porting process becomes more complex as these services need to be properly handled to ensure a seamless transition for the end user.

Rejection Codes

Rejection codes are used when a porting request is denied and specify the reasons for the rejection. There can be various reasons for rejection such as incorrect information provided, unpaid bills with the current provider, contractual obligations not met, or legal constraints. Rejection codes provide transparency and clarity to the requesting party regarding why the request was unsuccessful.

Table 2: Rejection codes and classifications for PNV requests

1: Invalid customer authorisation date

The "Invalid Customer Authorisation date" rejection code suggests that there is an issue with the date provided in the authorisation. This could be due to various reasons, such as:

  • Incorrect Date: The date specified for the porting may be outside of the acceptable range, or it may be incorrectly formatted.
  • Future Date: The date may be too far in the future, and there may be limitations on how far in advance you can schedule a porting request.
  • Mismatched Dates: There could be discrepancies between the date on the authorisation form and the date provided to the telecommunications service provider.

2: Insufficient information supplied

The "insufficient information supplied" rejection code suggests that the provided information is lacking, incorrect, or does not meet the requirements specified by the telecommunications service providers or regulatory authorities. Common reasons for receiving this rejection code may include:

  • Missing or Incomplete Documentation: The required documents or forms for the porting request are not provided, or they are incomplete. Incorrect Information: The information supplied does not match the records held by the current provider, or it contains inaccuracies.
  • Lack of Customer Authorisation: The customer authorisation for the porting request may be missing or not properly completed.
  • Inconsistent Data: There may be inconsistencies or discrepancies between the information provided and the data held by the current provider.

3: Telephone number appears to belong to a completely different end customer

“Telephone numbers appear to belong to a completely different end customer" suggests that there is a significant discrepancy between the ownership or customer details on the porting request and the information held by the current provider. Common reasons for receiving this rejection code may include:

  • Customer Mismatch: The customer information provided in the porting request does not match the information held by the current provider.
  • Unauthorised Porting: Attempting to port a number that does not belong to you or your organisation, or without the proper authorisation.
  • Data Inaccuracy: There might be discrepancies or inaccuracies in the customer information provided in the porting request.

4: Telephone numbers relate to cancelled services or services pending cancellation  

If the number is associated with services that have been canceled, or if those services are pending cancellation, it may not be eligible for porting, and you may receive the "Telephone numbers relate to canceled services or services pending cancellation" rejection code. Common reasons for receiving this rejection code may include:‍

  • Canceled Services: The phone number is linked to services that have already been canceled, which means it is no longer associated with an active account.
  • Services Pending Cancellation: The services associated with the phone number are in the process of being canceled, and the number may not be eligible for porting until the cancellation process is completed. To address this rejection code, you typically need to wait until the services associated with the phone number have been fully canceled or resolved with the current provider.

5: Missing/invalid PNV Sequence Number

The "Missing/invalid PNV Sequence Number" rejection code suggests that there is an issue with this identifier. Common reasons for receiving this rejection code may include:

  • Missing Sequence Number: The PNV sequence number is not provided in the porting request.
  • Incorrect Sequence Number: The sequence number provided does not match the records held by the current provider.
  • Incorrect Sequence Number: The sequence number provided does not match the records held by the current provider.

6: Telephone numbers in the PNV request relate to services which are billed by a service provider other than the losing carrier

The "Telephone numbers in the PNV request relate to services which are billed by a service provider other than the losing carrier" rejection code implies that there is a mismatch between the billing arrangement and the porting request. This situation could arise for various reasons, including:

  • Incorrect Billing Information: The billing information provided in the porting request does not match the billing records held by the losing carrier.
  • Service Provider Misalignment: The phone numbers might be associated with services billed by another service provider, rather than the losing carrier.
  • Incomplete Billing Transfer: The billing relationship might not have been appropriately transferred from the original service provider to the losing carrier.

7: Telephone numbers are not found/not present on losing carrier’s network

The "Telephone numbers are not found/not present on the losing carrier's network" rejection code implies that the losing carrier does not have records of the specified phone numbers in its network. This could be due to several reasons, including:

  • Inactive or Disconnected Numbers: The phone numbers might have been disconnected, canceled, or made inactive with the losing carrier.
  • Incorrect Phone Numbers: The numbers provided for porting might be incorrect, or there may be discrepancies between the numbers you're attempting to port and the records held by the losing carrier.
  • Technical Errors: There may be technical issues or errors that prevent the losing carrier from verifying the numbers.

Porting Process

Process Overview: Cat A (Two Party)

  1. The customer submits a port request, and the losing carrier validates details.
  2. A Simple Notification Advice (SNA) is sent from the gaining carrier to the losing carrier via a Porting Notification Order (PNO).
  3. An SNA Confirmation Advice is returned to the gaining carrier.
  4. An Electronic Cutover Advice (ECA) is sent to the losing carrier, displaying their intent to initiate the port.
  5. The losing carrier provides Donor Routing by redirecting calls to the gaining carrier.
  6. An ECA Confirmation Advice is sent to the losing carrier to confirm the service has been transferred to the gaining carrier.
  7. The losing carrier updates the Ported Local Number Registry (PLNR) file with a list of the ported numbers.

Step 1 – Customer Authority

Before initiating the port, the gaining carrier must obtain Customer Authorisation (CA) for number porting. Typically, this involves the customer filling out a porting form containing the list of numbers to be ported, account details with the losing carrier, and the desired porting date.

Step 2 - Validation  

Before any technical processes commence, the gaining carrier must validate the porting request:   

  • Verify that the Customer Authority is less than 90 days old.
  • Record the requested numbers.

Usually, these steps are consolidated into a single form submitted by the customer in the first step.

Step 3 – The SNA PNO  

Upon confirming the validity of the porting request, the gaining carrier sends a SNA to the losing carrier via a PNO. The details of the PNO include:

  • Area Code & Telephone Number of the service to be ported.
  • Service Account number with the losing carrier.  
  • Porting Category set to Cat A.
  • Date of Customer Authority.

After the losing carrier has completed these checks, they will send either an SNA Confirmation Advice if the port request is valid, or an SNA Reject Advice that includes the phone number and the reason for rejection if the port request is found to be invalid.

If an SNA Confirmation Advice is received, it remains valid for 30 days. Beyond this period, the process may need to restart, and a new SNA PNO would need to be generated. Its advised for Cat A ports you submit these close to the actual dates your needing ports to occur.

Step 4 – Electronic Cutover Advice (ECA)

Following an SNA Confirmation Advice, the gaining carrier sends an ECA to the losing carrier.

The losing carrier verifies the validity of the SNA and the ECA, ensuring that they are recent. If satisfied, they send an ECA Confirmation Advice within max 2 hours and majority 30 mins. This marks the initiation of the porting process. The losing carrier temporarily redirects calls to the gaining carrier.

Finally, the losing carrier sends an ECA to confirm that they have processed the port out from their network. Within a day of the port completion, the losing carrier updates the Ported Local Number Registry (PLNR) to reflect the service's successful port and the gaining carrier's identifier. PLNR is a text file containing a list of numbers allocated to the losing carrier, including carrier codes for routing purposes. Other carriers use this data to update their routing tables.

Process Overview: Cat C

1. A Complex Notification Advice is sent to the losing carrier, and a CNA Receipt Advice is returned to the gaining carrier to confirm receipt.

2. The project managers on either side agree upon a cutover date and time for the port.

3. The port is initiated, and the PLNR is updated.

Step 1 – Complex Notification Advice (CNA)

To initiate the porting process, the gaining carrier submits a CNA to the losing carrier. This submission includes customer details, the list of numbers/services to be ported, the unique batch number, and the gaining carrier project manager. Upon receipt of the CNA, the losing carrier sends a CNA Receipt Advice to confirm and initiate the validation process.  

Step 2 – CNA Confirmation Advice

If the validation process indicates a lack of verification, deeming the CNA request invalid, the losing carrier responds with a CNA Reject Advice. This response includes a list of services and corresponding rejection codes for each rejected service.

However, if the CNA is considered valid, the losing carrier provides a CNA Confirmation Advice. This includes the losing carrier’s project manager and the gaining carrier’s batch number. This advice is dispatched within 5 days of receiving the initial validation.

Step 3 – Complex Cutover Advice (CCA)

Upon receiving the CNA Confirmation Advice, the project managers of the port agree upon a cutover date and time for the port.

The agreed-upon date and time for the port are communicated by the gaining carrier to the losing carrier through a Complex Cutover Advice (CCA). The CCA contains the gaining carrier’s batch number and the agreed date and time.

If the details of the CCA align with the previously agreed time with the losing carrier, they will respond with a CCA Confirmation Advice to acknowledge receipt.

Step 4 – The Porting
At the agreed-upon date and time, both carriers carry out the porting process from their respective organisational standpoints. Typically, the losing carrier provides Donor Transit Routing, forwarding, or redirecting calls to the ported-out number to the new carrier.

The gaining carrier has an activation target of 30 mins to 2 hours.

Within a day of the port's completion, the losing carrier updates the PLNR. All carriers are required to update routing tables to ensure calls are routed directly to new gaining carriers and the removal of Donor Routing on the losing carrier's switch.  


CSP - Carriage Service Provider: A telecommunications service provider.

ACMA - Australian Communications and Media Authority: The regulatory body for communications and media in Australia.

ACA - Australian Communications Authority: The predecessor to ACMA.

Local Numbers - Geo numbers or landlines.

Portable Service - A service that allows customers to keep their phone numbers when switching Carriage Service Providers.

Local Number Portability (LNP) - The process of transferring phone numbers from one carrier to another.

Comms Alliance - An industry association for the Australian communications industry.

ISDN - Integrated Services Digital Network: A digital communication standard.

PSTN - Public Switched Telephone Network: A traditional landline telephone system.

POTS - Plain Old Telephone Service: Another term for traditional telephone service.

NBN - National Broadband Network: Australia's high-speed broadband network.

VoIP - Voice over Internet Protocol: Technology for making voice calls over the internet.

SIP - Session Initiation Protocol: A communication protocol used for voice and video calls over the internet.

Cat A - Category A: Refers to simple number porting, typically involving single PSTN/POTS lines.

Cat C - Category C: Refers to complex number porting, used for non-standard or more intricate porting requests.

Customer Authority (CA) - The customer's permission to port their number.

SNA - Simple Notification Advice: Part of the Cat A porting process.

PNO - Porting Notification Order: A form used to initiate the Cat A porting process.

ECA - Electronic Cutover Advice: Part of the Cat A porting process.

PLNR - Ported Local Number Registry: A list of ported numbers and their associated carriers.

Donor Routing - Temporary routing of calls to the new carrier during porting.

PNV - Porting Number Validation: A process to validate the portability of numbers.

CNA - Complex Notification Advice: Part of the Cat C porting process.

CNA Receipt Advice - A confirmation that the losing carrier has received the CNA.

CNA Confirmation Advice - Confirmation that the CNA is valid.

Complex Cutover Advice (CCA) - Part of the Cat C porting process.

CNA Confirmation Advice - Confirmation of the agreed-upon date and time for the port.

ECA Confirmation Advice - Confirmation that the port has been processed.

Electronic Completion Advice (ECA) - Confirmation of the completion of the port.

ENUM - Telephone Number Mapping: A protocol for mapping phone numbers to internet resources.  

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