Definitions

VoLTE - Voice over LTE
'VoLTE' or 'Voice over LTE' is a software system that provides call functionality on 4G/LTE Networks.
Unlike 2G/3G, 4G & 5G have no built-in calling functionlity, inluding for Emergency Calling. 4G/LTE & 5G are Data only standards are rely on VoLTE (which is a type of VoIP calling) to provide access to call service. Not all 4G/LTE devices support VoLTE, or on all networks.

IMEI
The IMEI (International Mobile Equipment Identity) is a unique 15-digit code that identifies a mobile device, such as a smartphone, tablet, or other mobile device, on a network. It's similar to a serial number but specifically used for identifying mobile devices.
In addition to the IMEI, devices also send the 'IMEI-SV' (Software Version) indicator to the network. This two digit number indicates what general revision of Software is installed on the device.
The SV is specific to a given model, two devices with the same Android version and software build date can have different IMEI-SV values.
To Obtain a device IMEI type *#06# in the dialer.

TAC
The Type Allocation Code (TAC) is an 8-digit number that identifies the brand and model of a mobile device. It's the first eight digits of the 15-digit International Mobile Equipment Identity (IMEI). The first 8 Digits of the IMEI (the TAC) can be different between identical makes and models of phones, alternative TACs are frequently used for different batches and production runs of products. Alternative Colour Variants and Storage capacities of the same phone model can also have different TACs.

Device is Blocked
Blocked from all services, incl Calls, Data & SMS
Device is NOT Blocked
Not Blocked and is 'Compatible', should work for VoLTE Emergency Calls. Note: VoLTE Calls may not work depending on the model
Reduced Coverage
Device lacks LTE Band 28 700MHz (Primary Optus Band) and may have reduced mobile coverage in areas with only 700MHz

Blocked
Blocked from all services, incl Calls, Data & SMS
Not Blocked
Not Blocked and is 'Compatible' (Whitelisted), should work for normal VoLTE Calls & Emergency Calls
TAC Not blocked
Not Whitelisted as 'Compatible', not (yet) Blacklisted. This is a hidden Category for devices with an unknown status on Telstra's Checker 'WDA_Ref_Not_blocked'.
This category represents devices that exist within Telstra's device Database where they don't have any information about if the phone works or not, some devices with this category are also unreleased or don't exist, or otherwise are not in use.
Band 28 Limited
Device lacks LTE Band 28 700MHz (Primary Telstra Band) and may have reduced mobile coverage in areas with only 700MHz
Function Limited
Limited VoLTE support on all networks, Data & SMS Only.
Some devices have firmware that only enables VoLTE Calling on some networks but VoLTE Emergency Calls work on all networks, frequently these are Samsung devices but there are Non-Samsung Devices that are also technically 'Function Limited' that are Blocked.
Not Found
Not Present in the Telstra Database
Not Phone
Classifed as not a Phone
IoT Devices, Watches, Tablets, only Mobile Phones are within the scope of the device blocking legislation

Blocked
Blocked from all services, incl Calls, Data & SMS
Not Blocked
Not Blocked and is 'Compatible' - Vodafone or 3498 (SMS 'Checker') Data, as of Q1 2025 Vodafone still has no public IMEI/TAC Checker Tool
Not Blocked - AMTA
Whitelisted as OK & 'Compatible' by AMTA (Australian Mobile Telecommunications Association) - (October 2024 Data)
Not Blocked - User
Not Blocked - User Reported Data, may not be accurate
Unknown
Support Status Unknown due to a lack of public TPG/Vodafone data

Optus Network MVNOs

Telstra Network MVNOs

Vodafone Network MVNOs

Note: Not all MVNOs are listed