Excise (Mass of CNG) Determination 2016 (No.2) 2016

The central legal and technical concepts in this determination are dutiable quantity, excisable CNG, measuring equipment capability, permitted conversion methods, aggregated clearances, accounting period, excise licensed establishment, and delegated discretion by the Commissioner.

• Dutiable quantity and mass: The determination requires the dutiable quantity for excisable CNG to be expressed as mass in kilograms (para 8). All acceptable methods are therefore pathways to produce a mass figure that will be used to calculate excise liability under the Excise Act and the Schedule to the Excise Tariff Act 1921 (para 6).

• Excisable CNG: The instrument applies only to CNG that falls within sub‑item 10.19C of the Schedule to the Excise Tariff Act 1921, that is delivered for home consumption under s 61C of the Excise Act (para 6). The term “Excisable CNG” is defined in the determination (para 14).

• Measuring equipment capability: The person’s measurement capability determines which set of methods is mandatory or available. If measuring equipment can differentiate excisable quantities from non‑excisable gas, the person must use one of Methods 1 to 3 (para 9). If the equipment cannot differentiate and aggregated clearances do not exceed 150,000 kg per accounting period, Methods 4 and 5 (apportionment methods) are available (para 10).

• Methods of conversion:

  • Method 1: Direct mass measurement where equipment measures in kilograms (para 9 Method 1).
  • Method 2: Energy measurement conversion where equipment records energy (joules); conversion to kilograms may use the conversion factor in Section 24(3) of the Excise Regulation 2015, or a conversion factor derived from composition by mole fraction using ISO 6976‑1995 (para 9 Method 2).
  • Method 3: Volume measurement conversion where equipment measures cubic metres; this has two alternative sub‑paths to mass , convert volume to energy (MJ) using heating value and correction/pressure factors from the gas distributor’s most recent tax invoice or averaging those values over an accounting period, then convert MJ to kilograms using the rate in Section 24(3) of the Excise Regulation 2015; or correct measured volume to standard reference conditions using AS ISO 13443‑2007 and then apply the mole‑fraction conversion per ISO 6976‑1995 (para 9 Method 3).
  • Methods 4 and 5: Measured constructive or measured deductive apportionment methods, allowed where measuring equipment cannot differentiate and where aggregated clearances are within the 150,000 kg threshold (para 10).

• Aggregated clearances and threshold: “Aggregated clearances” is defined as the mass of CNG delivered for home consumption by the person in the accounting period from excise licensed establishments based on historical data, or the mass reasonably expected if no historical data exists (para 14). The threshold of 150,000 kilograms per accounting period gates the availability of Methods 4 and 5 (para 10).

• Accounting period and CEO discretion: “Accounting period” is defined by reference to section 18 of the Income Tax Assessment Act 1936 (a 12 month period), or another period approved in writing by the CEO (para 14). The CEO has authority to approve alternative accounting periods and may authorise in writing a person to use more than one method per excise licensed establishment within an accounting period (para 13). The instrument itself is made under s 65 of the Excise Act which gives the CEO power to determine rules for working out volume or weight of excisable goods (para 6 Object).

• Incorporated standards and version locking: The determination requires use of AS ISO 13443‑2007 and ISO 6976‑1995 as they were current at commencement (para 12). This fixes the technical methods to specific published versions rather than leaving them open to later amendments unless the instrument is changed.

These concepts define a compliance regime where the primary administrative action is selection and application of a permitted conversion method, subject to capability, volume thresholds, and CEO authorisations. The determination connects to external rules for conversion factors and to specific industry standards for calorific values, density, Wobbe index and standard reference conditions.

The determination affects persons involved with producing, handling or delivering CNG that is potentially excisable under sub‑item 10.19C of the Schedule to the Excise Tariff Act 1921 and which is delivered for home consumption under section 61C of the Excise Act. The instrument repeatedly frames obligations in terms of “a person” who must calculate the mass of excisable CNG delivered into home consumption (para 8 and para 9). In practice those persons will include operators of excise licensed establishments as defined in the instrument and issued an Excise licence under section 39A of the Excise Act (para 14).

Key affected groups are therefore:

• Excise licence holders and operators of excise licensed establishments who deliver CNG for home consumption (para 14).
• Entities whose measuring equipment differentiates excisable CNG from other gas. These persons are required to use one of Methods 1 to 3 to determine mass (para 9).
• Entities whose measuring equipment cannot differentiate excisable from non‑excisable volumes. These persons may use the constructive or deductive apportionment Methods 4 and 5 only where aggregated clearances do not exceed 150,000 kg per accounting period (para 10).
• Small operators or those with low anticipated deliveries: the 150,000 kg aggregated clearances threshold creates a boundary that affects small‑scale suppliers differently from large suppliers. “Aggregated clearances” is defined so that if historical or reasonably expected deliveries exceed the threshold in an accounting period, the person cannot use Methods 4 or 5 (para 10, para 14).
• Persons relying on distributor data: Method 3(a)(i) requires use of heating value and correction/pressure factors “as supplied by your gas distributor in your most recent tax invoice” or averaged over an accounting period (para 9 Method 3(a)(i)). That provision brings gas distributors into the compliance chain because their tax invoices and reported heating values become the data source for conversion.
• Persons who seek to adopt a different accounting period or to use more than one method per establishment: the CEO must approve alternative accounting periods or authorise use of multiple methods in writing (para 14 definition and para 13).

The instrument therefore places obligations mainly on the taxpayer side (licensees delivering CNG for home consumption) to perform specific measurements, conversions and apportionments. The Commissioner retains administrative discretion to approve alternative accounting periods and permit use of multiple methods per excise licensed establishment (paras 13 and 14). The instrument also imposes indirect procedural impacts on gas distributors, whose invoices and supplied heating values are expressly required inputs for one conversion path (para 9 Method 3(a)(i)).

The determination imposes several specific duties on persons responsible for calculating the mass of excisable CNG and sets a limited range of administrative rights and discretions held by the Commissioner.

Duties imposed on the person calculating mass

• Calculate the dutiable quantity as mass in kilograms for excisable CNG delivered into home consumption (para 8). The instrument frames the process as a mandatory first step before determining excise duty payable.
• Where the person's measuring equipment can differentiate excisable CNG from other gas produced or gas used, the person must, subject to para 13, calculate mass using one of Methods 1, 2 or 3 (para 9). Those methods are mandatory options in that scenario; the person must pick one and apply it for the accounting period (para 13).
• Where the measuring equipment cannot differentiate excisable quantities and aggregated clearances do not exceed 150,000 kg per accounting period, the person may use Method 4 (measured constructive apportionment) or Method 5 (measured deductive apportionment) subject to para 13 (para 10). These methods are conditional permissions, not obligations.
• For Methods 4 and 5, use appropriate reliable measures as the basis for apportionment. The determination lists examples of “appropriate reliable measures”, including gas flow meter equipment, vehicle odometer readings, route distances, kilowatt hours of electricity generated, hours of operation and average hourly fuel consumption (para 11). The list is illustrative of the types of measurable proxies the Commissioner will accept; the instrument frames them as measures “that may be used”.
• Use the specified versions of incorporated standards AS ISO 13443‑2007 and ISO 6976‑1995 that were current at commencement when applying Method 3 or the mole‑fraction based conversion option (para 12).

Administrative constraints and rights

• A person must use only one Method for each excise licensed establishment for the duration of an accounting period unless authorised in writing by the CEO to do otherwise (para 13). This is a duty to maintain method consistency per establishment and per accounting period, with a formal written exception process.
• The CEO has express rights of discretion to approve alternative accounting periods and to authorise in writing use of more than one method per establishment during an accounting period. The definition of accounting period references section 18 of the Income Tax Assessment Act 1936 but allows another period approved in writing by the CEO (para 14).
• The Commissioner’s statutory authority to make the determination derives from s 65 of the Excise Act. The instrument itself is a legislative instrument (paras 5 and 6). The CEO’s role therefore includes both creating and enforcing the permissible methods for mass calculation, and the instrument preserves written authorisation processes where departure from the one‑method rule or from the default accounting period is required (paras 13 and 14).

Rights and limitations not created by the instrument

• The determination does not itself create or alter excise rates, nor does it set penalties or enforcement mechanisms. It prescribes technical conversion rules only and relies on the broader statutory framework of the Excise Act and associated regulations and tariffs for enforcement consequences (paras 5 and 6).
• The instrument does not create an express right to a particular conversion method beyond the listed options. Where a person seeks an arrangement not covered by Methods 1-5 or the defined measures, the mechanism is to seek written CEO authorisation (para 13).

In sum, the principal duties are technical and procedural: select an approved method consistent with measuring capability, apply that method consistently per establishment per accounting period, use specified industry standards where required, and use distributor‑supplied data where the method requires it. The principal rights are narrow and administrative: seek written authorisation from the CEO for an alternative accounting period or to deviate from the one‑method rule.

The determination itself does not specify monetary penalties, criminal offences, audit powers or enforcement procedures. It is a ruleset for calculating the dutiable quantity of CNG and is expressly made under section 65 of the Excise Act 1901 (paras 5 and 6). Enforcement and penalty regimes will therefore flow from the broader statutory architecture: the Excise Act, the Excise Tariff Act 1921, the Excise Regulation 2015 and other applicable taxation‑administration laws. The instrument refers to those statutes and regulations for substantive treatment,most notably it relies on the conversion factor stipulated in Section 24(3) of the Excise Regulation 2015 when providing conversion routes (para 9 Methods 2 and 3).

Concrete enforcement mechanics implied by the instrument

• The instrument places an obligation on the person calculating mass to use an approved method and to adhere to the one‑method‑per‑establishment per accounting period rule unless the CEO authorises otherwise in writing (para 13). Non‑compliance with that rule is a failure to follow the Commissioner’s determination; consequences for such failures would be determined under the Excise Act’s compliance and penalty provisions rather than inside this instrument.
• The instrument requires reliance on specified standards and distributor-supplied data. Failure to use the specified AS/ISO methods where required or to obtain and apply the distributor’s heating values as specified could result in the Commissioner treating declared dutiable quantities as incorrect, with whatever assessment and recovery powers the Excise Act confers.

Discretion and administrative control

• The CEO retains written discretion to authorise departures from the method consistency rule and to approve alternate accounting periods (paras 13 and 14). The instrument therefore places the administrative burden on the Commissioner to exercise that discretion and on taxpayers to apply for written authorisations where necessary.

What is not in the instrument

• The determination does not list sanctions, inspection rights, documentary retention requirements or audit timelines. It also does not identify the process or criteria the CEO will use when deciding whether to grant written authorisation for alternate methods or accounting periods. For specific enforcement, penalty or compliance timetable details, practitioners must read the Excise Act, related regulations and the taxpayer’s excise licence conditions. The determination supplies the technical conversion rules only.

In practice, enforcement will involve assessing whether a taxpayer has applied an allowed method correctly and consistently and whether any apportionments or conversions were based on the specified standards or distributor information as required. The Commissioner’s statutory audit, assessment and penalty powers under the Excise Act would then be the instruments for any remedial action.

This determination is an instrument interconnected with several statutes and technical standards. The instrument itself repeatedly cross‑references primary legislation and subordinate instruments, and it incorporates industry standards by reference. The principal interactions are as follows, with the specific paragraph references in the determination.

Excise Act 1901

• The determination is made under section 65 of the Excise Act, which empowers the Commissioner (CEO) to determine rules for working out the volume or weight of excisable goods (para 6 Object). It applies to CNG delivered for home consumption pursuant to section 61C of the Excise Act (para 6). The determination therefore functions as a technical rule within the Excise Act framework: it does not alter underlying excise duties, but it informs how dutiable quantities will be calculated for the purposes of that Act.

Excise Tariff Act 1921

• The instrument applies only to CNG classified to sub‑item 10.19C of the Schedule to the Excise Tariff Act 1921 (para 6). That ties the determination to tariff classification. If the tariff classification were different, the determination would not apply. This interaction means that determining whether CNG is “excisable” under the tariff remains a preliminary legal question that affects whether these measurement rules apply.

Excise Regulation 2015

• The determination instructs persons to use the conversion factor stipulated in Section 24(3) of the Excise Regulation 2015 for certain conversion paths (para 9 Methods 2 and 3). Thus the instrument depends on an external prescribed conversion factor in a subordinate regulation. Any change to Section 24(3) of the Excise Regulation 2015 would affect Method 2 conversions from joules and the MJ‑to‑kg path in Method 3(a)(ii).

Income Tax Assessment Act 1936

• The definition of “accounting period” references section 18 of the Income Tax Assessment Act 1936 as the 12 month period adopted for income tax purposes, or another period approved in writing by the CEO (para 14). That links excise accounting periods to income tax accounting practice by default, yet preserves CEO flexibility to approve a different period in writing.

Legislation Act 2003

• The instrument is explicitly a legislative instrument for the purposes of the Legislation Act 2003 (para 5). That means it is subject to the publication, disallowance and other administrative procedures that apply to legislative instruments under the Legislation Act. Parliamentary or procedural remedies available under that Act could be relevant to interested parties.

Australian and International Standards (AS ISO 13443‑2007 and ISO 6976‑1995)

• The determination requires the use of these standards as current at commencement for specific conversion steps: AS ISO 13443‑2007 for standard reference conditions (101.325 kPa and 288.15 K) and ISO 6976‑1995 for mole fraction‑based conversion of composition to calorific value, density and Wobbe index (paras 9 Method 3(b) and para 12). Those standards are incorporated by reference and the determination fixes the versions current at commencement (para 12). Interaction with standards law and rules on incorporated instruments is therefore relevant: revisions to those standards after commencement are not automatically incorporated unless the instrument is updated.

Other administrative instruments and licences

• The definition of “excise licensed establishment” ties the instrument to excise licences issued under section 39A of the Excise Act (para 14). Licence conditions, administrative guidance from the Commissioner and other excise‑related legislative instruments will influence practical compliance.

Net effect of interactions

• The determination operates as a technical bridge between measurement practices and excise calculation under the Excise Act and associated tariff schedule. It references conversion factors, accounting period definitions and industry standards that sit in other instruments or bodies of law. Changes in those external instruments could change the practical operation of the methods prescribed here. For compliance and dispute resolution, the determination must therefore be read in conjunction with the Excise Act, the Excise Tariff Act 1921, the Excise Regulation 2015, the Legislation Act 2003, the Income Tax Assessment Act 1936 and the specified AS/ISO standards.

This instrument contains a concise internal amendment history limited to its own immediate predecessor and commencement detail. The text records two discrete historical actions.

• Repeal of prior determination: The determination expressly repeals Excise (Mass of CNG) Determination 2016 (No. 1) F2016L0013 on commencement (para 3). That is the only repeal recorded in the instrument. The replacement suggests the Commissioner intended to supersede the earlier technical ruleset with this version effective from the date the instrument commenced.

• Commencement timing: The determination commences on the day after registration (para 2). The instrument is dated 13 September 2016 and signed by Deborah Jenkins, Acting Deputy Commissioner of Taxation. The combination of the date on the instrument and the commencement provision fixes the operative start date as the day after registration on the Federal Register of Legislation rather than the signature date alone (para 2 and signature block).

What is not in the amendment history

• The instrument does not record any prior amendments to itself, and it does not list transitional arrangements or grandfathering provisions for taxpayers transitioning from the repealed earlier determination to the new rules. It also does not record any subsequent amendments or later versions; readers must consult the Federal Register of Legislation or the Commissioner’s publications to check for later amendments or replacements.

Practical consequence for practitioners

• Because the instrument repeals immediately its predecessor on commencement, operators who had been complying with the earlier determination must check whether the method options, thresholds or standard versions have changed between the instruments. The determination fixes the versions of the AS/ISO standards “that are current at the time of commencement” (para 12), which means any later revisions to those standards are not captured unless the instrument is updated.

Administrative note

• Since the instrument is a legislative instrument under the Legislation Act 2003 (para 5), any further amendments must follow the procedures applicable to legislative instruments, including registration and potential disallowance processes. The instrument itself does not record any parliamentary disallowance or other procedural history; for current status and any amendments practitioners must consult the public register.

The text of this determination contains no references to litigation, court decisions or disputes. It does not cite any cases, and it records no judicial challenges, tribunal determinations or precedential rulings relevant to its interpretation. The instrument is a technical administrative determination made under s 65 of the Excise Act and does not itself include or summarise any litigation history.

Implication for research and advice

• Because there is no litigation history in the instrument, practitioners seeking authoritative interpretations, contested applications of the methods, or rulings on edge cases will need to search external sources: decisions under the Excise Act, administrative rulings issued by the Commissioner, tribunal or court judgments that address measurement and conversion disputes, and any published private binding rulings or public guidance relating to excisable CNG mass calculations. Such materials are not present in the text supplied here.

Points of uncertainty that often produce litigation in similar contexts

• The determination sets out discrete technical choices and discretionary written authorisation processes. Common litigation drivers in excise measurement disputes typically include: the validity of apportionment methodologies, the acceptability of proxy measures for apportionment, the adequacy of records supporting distributor‑supplied heating values, and the Commissioner’s exercise of written discretions such as authorising different methods or accounting periods. None of these hypothetical dispute instances are recorded in the instrument itself. Practitioners should therefore treat the instrument as a ruleset and check for any external case law or rulings that have interpreted similar provisions under the Excise Act or related determinations.

The determination is short and technical, but it contains multiple operational traps for taxpayers and advisers. The following are concrete areas where a taxpayer can face compliance risk or operational difficulty, drawn directly from the wording and structure of the instrument.

Single method constraint per establishment per accounting period (para 13)

• A person must use only one Method for each excise licensed establishment for the duration of an accounting period unless authorised in writing by the CEO (para 13). The administrative requirement of method consistency means that taxpayers cannot switch between measurement or conversion approaches mid‑period without prior written approval. Non‑compliance could expose the declared dutiable quantity to challenge, and the instrument does not explain how the CEO will respond to after‑the‑fact method changes.

Measuring equipment capability test (para 9)

• The gating question that determines whether Methods 1-3 or Methods 4-5 apply is whether the person’s measuring equipment can differentiate quantities of excisable CNG from other quantities of CNG produced or natural gas used (para 9). That capability will often be a factual and technical question. Taxpayers who err in their self‑assessment of capability could choose an incorrect method set. The instrument does not prescribe an evidentiary standard for demonstrating capability, nor a certification process.

150,000 kg aggregated clearances threshold (para 10)

• If aggregated clearances exceed 150,000 kg per accounting period, Methods 4 and 5 are not available (para 10). The definition of “aggregated clearances” allows use of historical data or expectations where historical data is not available (para 14). A taxpayer who underestimates expected deliveries may trigger a retrospective incompatibility with Methods 4 and 5. The instrument does not provide transitional protections for crossing the threshold mid‑period.

Dependency on distributor data and tax invoices (para 9 Method 3)

• One conversion route requires use of heating value and correction/pressure factors “as supplied by your gas distributor in your most recent tax invoice, or by applying an average … over an accounting period” (para 9 Method 3(a)(i)). If a distributor does not supply clear heating values or correction factors in its tax invoice, the person’s ability to use that conversion path may be impaired. The instrument does not specify a remedy if distributor invoices are incomplete or unavailable.

Version locking of standards (para 12)

• The instrument fixes the versions of AS ISO 13443‑2007 and ISO 6976‑1995 current at commencement for the relevant calculations (para 12). Users cannot rely on later, possibly clearer or altered versions unless the instrument is amended. This can be problematic if later standards clarify technical points or supply different computational conventions.

Reliance on Section 24(3) of the Excise Regulation 2015 (para 9 Methods 2 and 3)

• Several conversion pathways rely on the conversion factor in Section 24(3) of the Excise Regulation 2015. If that provision is amended, the appropriate conversion factor changes. The instrument does not itself contain the numerical factor; practitioners must cross‑check the Regulation.

Ambiguity in “appropriate reliable measures” for apportionment (para 11)

• The instrument lists example measures that “may be used” for Methods 4 and 5, but it does not set out criteria for when a measure is “appropriate” or “reliable”. That opens space for differing interpretations between taxpayers and the Commissioner over whether a chosen proxy measure is adequate.

No express recordkeeping or evidentiary standards in the determination

• The instrument does not state what records must be retained to support chosen methods, apportionments, or calculations. Practitioners must therefore default to the recordkeeping and evidence standards in the Excise Act and general taxation law, but this instrument does not make those expectations explicit.

CEO discretionary processes are unspecified (paras 13 and 14)

• The Commissioner can approve different accounting periods and authorise use of multiple methods in writing. The instrument does not set procedures, timelines or criteria for those written authorisations. That could result in delay or uncertainty for taxpayers seeking non‑standard arrangements.

Relevance to licence conditions (para 14)

• The definition of “excise licensed establishment” ties the instrument to licences issued under section 39A of the Excise Act. Licence terms and conditions could impose additional measurement, reporting or recordkeeping obligations beyond what appears in this determination. Practitioners must cross‑check licence obligations.

These “gotchas” follow directly from the determination’s structure and wording. Each creates a potential compliance cost or administrative risk that taxpayers should address in their internal controls, documentation and interactions with the Commissioner and with gas distributors.

The determination sets a limited, structured pathway for compliance. Compliance requires selection and application of an approved method, consistent use per excise licensed establishment for the accounting period, use of specified standards and reliance on prescribed conversion factors or distributor data where required. Below is a practical compliance checklist aligned to the instrument’s text and numbering.

1. Confirm applicability

• Verify that the CNG in question is classified to sub‑item 10.19C of the Schedule to the Excise Tariff Act 1921 and that deliveries are “for home consumption” under section 61C of the Excise Act (para 6). If not, this determination does not apply.

2. Determine measuring equipment capability

• Assess whether your measuring equipment can differentiate excisable CNG quantities from other CNG produced or natural gas used. This assessment determines whether you must use Methods 1-3 (if capable) or whether Methods 4-5 may be used (if not capable and aggregated clearances are within the threshold) (para 9 and para 10). Maintain documentation evidencing how the capability conclusion was reached.

3. Calculate aggregated clearances and check the 150,000 kg threshold

• Compute aggregated clearances for the accounting period using historical data or a reasonable expectation if historical data is not available, as defined by the instrument (para 14). If aggregated clearances exceed 150,000 kg per accounting period, do not use Methods 4 or 5 (para 10).

4. Choose and adopt a method per excise licensed establishment

• For each excise licensed establishment, select one conversion Method and apply it consistently for the accounting period (para 13). If you require a different method for a particular establishment or need to change methods within the period, apply in writing to the CEO for authorisation in advance (para 13).

5. Apply the chosen method correctly

• Method 1: Use direct kilogram readings from mass measuring equipment where available (para 9 Method 1).
• Method 2: If energy (joules) is measured, convert to kilograms using either the conversion factor in Section 24(3) of the Excise Regulation 2015, or use a mole‑fraction composition method per ISO 6976‑1995 (para 9 Method 2). Ensure you have access to the relevant conversion factor in the Excise Regulation.
• Method 3: If measuring in volume (m3), choose one of two sub‑paths:
  • Method 3(a): Convert cubic metres to megajoules using heating value and correction/pressure factors supplied by your gas distributor in your most recent tax invoice, or apply averaged values over an accounting period, then convert MJ to kilograms using Section 24(3) of the Excise Regulation 2015 (para 9 Method 3(a)). Keep copies of distributor tax invoices and any averaging calculations.
  • Method 3(b): Correct measured volumes to standard reference conditions (101.325 kPa and 288.15 K) using AS ISO 13443‑2007, then apply the mole‑fraction conversion per ISO 6976‑1995 (para 9 Method 3(b) and para 12).
• Methods 4 and 5: If equipment cannot differentiate and aggregated clearances are within 150,000 kg, apply a measured constructive or measured deductive apportionment using appropriate reliable measures (para 10). Use the illustrative measures listed (para 11) as starting points and retain the basis of selection and calculation. Examples include gas flow meter readings, odometer or route distances for vehicles, kWh generated, hours of operation, and average hourly fuel consumption (para 11).

6. Use specified standards and conversion factors

• Use AS ISO 13443‑2007 and ISO 6976‑1995 as they were current at commencement for the relevant corrections and mole‑fraction conversions (para 12). Use the conversion factor stipulated in Section 24(3) of the Excise Regulation 2015 where the determination refers to it (para 9 Methods 2 and 3).

7. Document and retain evidence

• Although the determination does not state express recordkeeping rules, the conversion paths rely on third‑party data (gas distributor tax invoices) and on calculated apportionments. Retain distributor invoices, records of heating values and correction factors, averaging calculations, raw meter data, apportionment logic and supporting calculations to substantiate declared mass. Also keep written approvals from the CEO for any deviations (paras 9, 11, 13).

8. Coordinate with gas distributors and fleet operators

• Where Method 3(a) is used, secure clear statements of heating value and correction/pressure factors from your gas distributor and ensure those values are included in the distributor’s tax invoice as required by the instrument (para 9 Method 3(a)(i)). If using vehicle or route proxies for apportionment, maintain reliable odometer logs, route documentation and operating hour records (para 11).

9. Anticipate change and apply for authorisations early

• If you expect to cross the 150,000 kg threshold, need to switch methods mid‑period, or require a different accounting period from the default 12 months, apply to the CEO in writing early because the instrument requires written authorisation for alternatives (paras 13 and 14).

10. Cross‑check regulatory and licence obligations

• Review your excise licence conditions under section 39A of the Excise Act and relevant provisions of the Excise Regulation and Excise Tariff Act. The determination is a technical rule; licence conditions and the Excise Act may impose additional reporting, recordkeeping or compliance obligations (para 14).

Following these steps aligns operational practice with the determination’s prescribed conversions and administrative constraints. Practitioners should maintain conservative records, coordinate with gas distributors to ensure invoice data meets the instrument’s expectations, and seek written CEO authorisations where consistency or accounting period needs require it.