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May 23, 2026
7 min read

How fleet operators report Scope 3 Category 1 under ESRS E1

ESRS E1 requires fleet managers to report Scope 3 Category 1 emissions from vehicle cleaning. How waterless valeting provides defensible per-service data.

What qualifies as Scope 3 Category 1 in a fleet context?

Scope 3 Category 1 covers purchased goods and services — everything a company buys from third parties that is not already captured in upstream Scope 3 Categories 2 through 8. For a fleet operator, that includes vehicle cleaning contracts, parts procurement, outsourced workshop services, and leased assets accounted for under the purchase model.

ESRS E1 paragraph AR 12–16 defines the reporting boundary explicitly. Category 1 includes all upstream (cradle-to-gate) emissions from the production of purchased goods and the delivery of purchased services. For a fleet cleaning contract, this chain runs from chemical manufacture through water supply, effluent treatment, the provider’s energy consumption, and staff logistics. Each link generates emissions that must be declared in Category 1 unless they are already counted in the provider’s Scope 1 or Scope 2 and the operator is applying a hybrid approach.

The materiality assessment under ESRS 2 determines whether vehicle cleaning needs separate disclosure. If external valeting represents more than 5% of total purchased goods spend, or if it falls in a category flagged as likely material for transport and automotive sector reporting, it cannot be excluded without documented justification in the Double Materiality Assessment. Most fleet operators with outsourced vehicle care will find it crosses the materiality threshold.

What data does ESRS E1 require for Category 1 reporting?

The standard mandates six specific disclosures per Category 1 sub-category:

  • Total gross Scope 3 emissions in tCO2e
  • A breakdown by significant sub-category (vehicle cleaning, parts, outsourced maintenance, and so on)
  • The calculation methodology applied: spend-based, supplier-specific, or hybrid
  • The percentage of emissions calculated using primary data versus secondary data (DEFRA factors, EEIO model coefficients, or similar)
  • A description of the data sources, assumptions, and estimation uncertainty level
  • The consolidation approach used (operational control, financial control, or equity share)

The phase-in timetable depends on company size. For undertakings already subject to NFRD, full ESRS E1 reporting applies from financial years beginning on or after 1 January 2025. For other large undertakings — those meeting two of three criteria: more than 250 employees, more than €40 million turnover, or more than €20 million total assets — the requirement starts from financial years beginning on or after 1 January 2026. Fleet managers whose parent organisation is in either group should already be compiling Category 1 data.

A separate transition applies to the assurance requirement. Limited assurance on all ESRS disclosures is required from year one; reasonable assurance follows by year three, in line with the European Commission’s phased implementation under Article 26 of the CSRD. That trajectory means data quality must improve over time — the standard expects suppliers of primary data to tighten their methodologies across reporting cycles.

Why traditional washing creates a Category 1 blind spot

Traditional fleet washing presents three structural problems that prevent accurate Category 1 reporting.

Wash methodWater volume per vehicleDischarge treatment dataProvider data quality
Automated tunnelVariable, metered per siteRarely available from operatorSupplier typically provides none
On-site pressure washVariable, hard to isolateUsually to drain, untreatedNo per-vehicle record
Mobile waterlessFixed input per vehicleNo dischargePer-service record available

Water volume uncertainty. When a vehicle goes through an automated tunnel wash, water consumption depends on wash cycle length, pressure settings, and whether the operator uses reclaim. Without submetering per vehicle, the fleet manager applies an average factor — which introduces error margins that compound across a fleet of hundreds or thousands of vehicles.

Discharge treatment. Every litre of wash water that runs off carries detergents, traffic film, and hydrocarbons. The treatment of this effluent — collection, transport to treatment works, chemical dosing, and sludge disposal — generates Category 1 emissions that most fleet operators never quantify. DEFRA’s 2024 GHG Conversion Factors for Company Reporting include emission factors for water supply (covering abstraction, treatment, and distribution) and for water treatment (covering collection and processing of wastewater). These are the fallback factors fleet managers resort to when provider-specific data does not exist, but they carry their own uncertainty margins.

Provider opacity. The wash facility’s own electricity consumption, chemical sourcing footprint, and staff travel to the site are all parts of Category 1 that the provider could disclose but rarely does. Without a data-sharing arrangement, the fleet operator falls back to spend-based estimates — the least accurate methodology permitted under ESRS E1.

How mobile waterless valeting removes the data gaps

A waterless system removes the two hardest variables from the Category 1 equation: water volume and effluent treatment. The service uses no water on site. There is no run-off, no discharge to treat, and no variable water consumption to estimate or meter.

For the fleet manager compiling Category 1 data, this means:

  • Water supply and treatment emissions fall to zero for the cleaning line item — the service provider supplies and contains all cleaning media within its own system
  • Chemical input is fixed per vehicle — every valet uses a known volume of pre-treatment and protectant, which maps directly to the chemical’s cradle-to-gate emission factor
  • Provider travel emissions do not arise — mobile valeting comes to the fleet yard, so there is no separate travel-to-wash-site leg to account for

Each valet produces a discrete record containing the vehicle class, outward postcode, service date, and treatment type applied. This record is primary supplier-specific data — the gold standard under ESRS E1’s methodology hierarchy. Primary data attracts a lower uncertainty weighting than spend-based or EEIO estimates, which improves the defensibility of the entire Category 1 disclosure.

For fleet operators in Surrey, our mobile car valeting in Esher and mobile car valeting in Weybridge services run the same waterless system and generate per-service records compatible with Category 1 reporting.

Mapping per-service valeting data to your ESG platform

The three fields most ESG platforms require for Scope 3 Category 1 are straightforward to populate from a valeting service record.

Category assignment. Vehicle cleaning — purchased service — belongs under the purchased goods and services category group. Most major ESG platforms allow tagging by service type within Category 1.

Geographic dimension. The vehicle’s outward postcode — for example KT, SW, or TW — provides the location context that some platforms use to apply regional DEFRA factors or to segment emissions by operational region.

Service frequency and vehicle class. Light commercial versus heavy commercial vehicles carry different upstream emission profiles. Recording vehicle class alongside each service allows the ESG platform to apply the correct emission factor per unit of spend or per service event.

Data for each of these fields can be provided by MMCC on request for services carried out under a fleet contract.

Building a defensible Category 1 audit trail through supplier-specific data

The ESRS E1 assurance trajectory — limited assurance in year one, reasonable assurance by year three — means your Category 1 numbers need a traceable data chain. Primary data from a supplier carries more weight than modelled estimates. Per-service records that are timestamped, postcode-tagged, and vehicle-classed form primary evidence.

The practical benefit for fleet managers: switching from traditional washing to a waterless mobile valeting provider with per-service data recording removes the need to estimate water consumption or effluent treatment entirely. It replaces DEFRA default factors and EEIO coefficients with actual service-level data points. Over a three-year assurance cycle, that improvement in data quality shows up directly in the methodology disclosure — the ratio of primary to secondary data shifts measurably in the right direction.

Fleet managers who want to understand how per-service data maps to their ESG platform can request a sample export through our Corporate fleet solutions page.