Tier 2 vs Tier 3, explained.

The difference is estimation versus measurement, and it changes both your budget and your timeline.

NUPRC's directive moves operators up what the IPCC calls the accuracy ladder. Tier 1 is generic emission factors multiplied by activity data, no longer sufficient for NUPRC from Q3 2026 onward. Tier 2 uses factors specific to the country or the operation, checked against metered data, the minimum acceptable basis today. Tier 3 requires direct measurement and continuous monitoring across every source, the required end state from January 2027.

What changes between the two, in practice

• Data basis: Tier 2 accepts calculation from metered volumes and standard factors. Tier 3 requires continuous, source-level measurement, meaning meters and monitoring in place at flares, vents and fugitive-emission points, not just at custody-transfer points.
• Reporting cadence: Tier 2 is compatible with a well-run monthly reconciliation cycle. Tier 3 is built for continuous data flow, so a monthly spreadsheet exercise stops being viable as the primary method.
• Cost and timeline: Tier 2 can often be reached with existing metering plus a disciplined reconciliation process. Tier 3 typically requires closing metering gaps first, then building the automated ingestion and validation layer on top, which is why operators without an internal MRV function are budgeting for it as a 2026 workstream rather than a January 2027 scramble.

Why the penalty structure raises the stakes on accuracy

Under the Flare Gas (Prevention of Waste and Pollution) Regulations 2018, producers at or above 10,000 barrels of oil per day are charged $2.00 per thousand standard cubic feet (Mscf) flared; producers below that threshold are charged $0.50 per Mscf. Methane is converted to CO₂ equivalent using its Global Warming Potential, roughly 28 times CO₂ over 100 years, so a small error in vented or fugitive volume at Tier 2 has an outsized effect once it is reconciled against production and reported. Moving to Tier 3 measurement is what lets an operator defend a figure rather than estimate one.

The practical read

Tier 2 is not a lesser obligation to be revisited later, it is this quarter's compulsory baseline. Tier 3 is the target architecture. The operators best positioned for January 2027 are the ones treating Tier 2 as the foundation for Tier 3, mapping IPCC factors and closing metering gaps now, rather than treating the two as separate projects.

Sources. NUPRC Directive on Standardised Templates & Measurement-Based Methane/GHG Reporting (2026); Flare Gas (Prevention of Waste and Pollution) Regulations 2018; IPCC emission factor tier guidance. Not legal or compliance advice. Confirm current obligations directly against NUPRC's published directives.