| Boundaries |
|---|
| Operational control misread | A building the company operates is reported as Scope 3 because the landlord pays the electricity bill | Operational control tested site by site, not by who pays the bill | 15% | Sometimes material |
|---|
| Sites or entities missing or counted twice | Leased sites, subsidiaries or joint ventures left out, or included in two entities' figures | The entity and site list against the consolidation approach | 20% | Sometimes material |
|---|
| Acquisitions and disposals not reflected | Part-year ownership not pro-rated, and the base year not recalculated | Structural changes and the base-year recalculation policy | 15% | Often material |
|---|
| Gases and completeness |
|---|
| Biomass and bioenergy reported as zero | Energy sold as “zero carbon” is zero CO2 only; methane and nitrous oxide from combustion are missed | Methane and nitrous oxide included, and biogenic CO2 reported separately | 25% | Sometimes material |
|---|
| F-gas records incomplete or unreliable | Missing top-up logs or engineer reports, or leakage assumed to be zero | Service records and refrigerant top-ups for each system | 60% | Sometimes material |
|---|
| Minor fuels and sources missing | Generators, LPG, heating oil or process emissions left out | Completeness of sources against each site's activities | 30% | Rarely material |
|---|
| Upstream energy omitted | Well-to-tank and transmission and distribution losses missing from Scope 3 | Coverage of Scope 3 category 3 | 20% | Often material |
|---|
| Emission factors |
|---|
| Out-of-date factors | Factors from a previous year applied to this year's activity | Factor year and version against the reporting period | 35% | Sometimes material |
|---|
| Unofficial factor sources | Factors from websites, software defaults or unreferenced sources | Traceability to recognised published sources | 25% | Sometimes material |
|---|
| UK spend factors applied overseas | UK spend-based factors used for overseas purchases or operations | Geographic match between each factor and the activity | 30% | Often material |
|---|
| Spend factors not adjusted for price year or currency | Current spend applied to factors from a different price year or currency | Inflation and currency adjustment | 50% | Often material |
|---|
| Gross and net calorific value mixed | Fuel energy on one calorific basis and the factor on the other | The calorific basis of the activity data and the factor | 20% | Sometimes material |
|---|
| Wrong unit conversions | Errors converting between litres, kilograms, cubic metres, kWh and therms | Recalculation of every conversion | 10% | Often material |
|---|
| Supplier factors including other emissions | Supplier-specific factors that already include downstream or other-scope emissions, so they are counted twice | The boundary of each supplier-specific factor | 15% | Sometimes material |
|---|
| Scope 2 |
|---|
| No location-based figure | Only market-based Scope 2 reported | Both location-based and market-based figures reported | 30% | Often material |
|---|
| Unsupported renewable claims | Green tariffs claimed without qualifying certificates such as REGOs, or no residual mix applied | Contractual instruments against the Scope 2 quality criteria | 20% | Often material |
|---|
| Travel and transport |
|---|
| Flights reported as CO2 only | Travel company reports omit other gases and the radiative forcing uplift | The factor basis, and disclosure of the radiative forcing choice | 45% | Sometimes material |
|---|
| Electric vehicles reported as zero | EV taxis or cars reported as zero emissions, ignoring the electricity used | Electricity-based factors for EV travel | 30% | Rarely material |
|---|
| Grey fleet and mileage gaps | Mileage claims missing, or default vehicle types applied to known vehicles | Mileage records and vehicle-specific factors | 15% | Sometimes material |
|---|
| Scope 3 |
|---|
| Offsets netted off | Suppliers or the organisation deduct offsets, often of doubtful quality, from reported emissions | Gross emissions reported, with offsets disclosed separately | 10% | Often material |
|---|
| Commuting cut without homeworking added | Lower commuting claimed, but the emissions from more homeworking are missing | Commuting and homeworking assessed together | 30% | Rarely material |
|---|
| Double counting between categories | For example, freight counted in purchased goods spend and again in transport | Allocation of each activity to one category | 20% | Sometimes material |
|---|
| Calculations and data |
|---|
| Spreadsheet formula errors | COUNT used instead of SUM, inserted rows outside totals, broken links | Recalculation of totals from source data | 40% | Sometimes material |
|---|
| Data periods misaligned | Invoices or meter reads that do not match the reporting year, or estimated bills never corrected | Period alignment and accruals | 45% | Sometimes material |
|---|
| Transcription errors | Figures copied wrongly from bills, meters or supplier reports | A sample traced back to source documents | 30% | Sometimes material |
|---|
| Estimates not quantified or disclosed | Estimates and extrapolations used without stating their size or method | The share of estimated data and how it is disclosed | 55% | Sometimes material |
|---|
| Method and documentation |
|---|
| Methodology too vague to reconstruct | Another person could not rebuild the footprint from the methodology | Re-performance of the calculation from the methodology | 30% | Sometimes material |
|---|
| No audit trail | Reported figures cannot be traced back to invoices, meter reads or records | Tracing from each total back to source | 35% | Sometimes material |
|---|
| Exclusions not justified | Sources excluded as immaterial without assessment or disclosure | The rationale and estimated size of each exclusion | 40% | Sometimes material |
|---|
| Inconsistent methods year to year | Methods changed without restating the prior year or disclosing the change | Consistency with the prior year and restatement | 25% | Sometimes material |
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