SECR reporting for manufacturing — UK compliance guide

If you operate a UK manufacturing business turning over £36M+ (or holding £18M+ in assets, or employing 250+ people), this guide covers what your SECR filing has to address and where most manufacturers get it wrong.

SECR challenges specific to manufacturing

Manufacturers face four problems generic SECR templates don't handle:

1. Process emissions vs combustion emissions. Cement kilns, lime calcination, glass melting and steel production all release CO₂ from the chemical process itself, separate from the fuel that heats them. Your SECR report has to disclose both, and most off-the-shelf calculators only handle the combustion side.
2. Site-level metering granularity. Most manufacturers run multiple sites, each with multiple meters — often half-hourly data on the main grid supply and monthly invoices on gas and red diesel. Reconciling these for SECR, especially across an acquisition year, eats consultant time if your data isn't structured.
3. The intensity ratio your investors actually compare against. SECR requires an intensity ratio; manufacturing investors and trade buyers expect tCO₂e per tonne of product (or per unit of saleable output), not per £1M of turnover. Filing the wrong one looks naive.
4. Embodied carbon in raw materials. SECR scope 3 is voluntary, but if your customers are filing CSRD or CDP (most large UK manufacturers' customers now are), they'll request your scope 3 category 1 (purchased goods and services) data. Plan for it in year 1 even if you don't disclose it.

Typical scope 1 emissions in manufacturing

Scope 1 covers direct emissions from sources you own or control. For a UK manufacturer this usually means:

• Natural gas combustion — boilers, ovens, kilns, dryers, space heating in production halls
• Process emissions — CO₂ released from chemical reactions (cement, lime, glass, ammonia, steel, ceramics)
• On-site gas turbines and CHP — many large manufacturers run combined heat and power for resilience or process steam
• Diesel and red diesel — back-up generators, forklifts (where not electric), site vehicles, mobile plant
• LPG and propane — for forklift fleets, off-mains heating, some process applications
• Refrigerant leakage — chillers on cooling circuits, comfort cooling, refrigerated finished-goods storage. F-gases like R-410A, R-404A and R-134a have global warming potentials thousands of times higher than CO₂; even small leaks materially move the scope 1 number
• Welding gases — some shielding gases and carbon-containing process gases count

The single most-missed source we see when taking over a previous filer's manufacturing SECR report: refrigerant top-ups. Your maintenance contractor logs kg of refrigerant added each year — that data lives in service reports, not in finance.

Typical scope 2 emissions in manufacturing

Scope 2 is purchased energy — overwhelmingly grid electricity in UK manufacturing. The question is whether you report location-based, market-based, or both.

• Location-based — uses the UK grid average emission factor (DEFRA publishes this annually). Everyone reports this.
• Market-based — reflects what you actually procured. If you buy a green tariff backed by REGOs (Renewable Energy Guarantees of Origin), market-based emissions can drop to near-zero. SECR doesn't strictly mandate market-based, but it's increasingly expected, and your customers' CDP submissions ask for it.

If you've signed a Power Purchase Agreement (PPA) with a UK wind or solar farm, you'll need to defend the additionality claim in your narrative section. Auditors and informed buyers will check whether you're claiming an emissions reduction the original generator's offtaker is also claiming.

Scope 3 considerations for manufacturing

SECR scope 3 disclosure is voluntary, but the relevant categories for manufacturers are:

• Category 1 — Purchased goods and services (almost always the biggest line) — raw materials, components, packaging, third-party services. Steel, aluminium, plastics and chemicals all carry high embodied carbon factors
• Category 4 — Upstream transportation — inbound logistics from suppliers
• Category 5 — Waste from operations — production waste, off-spec scrap
• Category 6 — Business travel
• Category 7 — Employee commuting
• Category 9 — Downstream transportation — outbound logistics to customers and distributors
• Category 11 — Use of sold products (if you sell energy-consuming products — pumps, motors, appliances, vehicles, equipment)
• Category 12 — End-of-life treatment of sold products

Spend-based methodology (£ spent × industry emission factor per £) is acceptable for year 1, but auditors push hard for activity-based data (kg material × kg-CO₂e per kg) on the top three categories by emissions in year 2 onwards.

Common mistakes manufacturers make

1. Forgetting process emissions — only counting the gas burned, not the CO₂ released by the chemical reaction
2. Missing F-gas refrigerant leakage — kg of R-404A top-up data sits in maintenance reports, not finance
3. Reporting kWh of grid electricity but ignoring on-site solar generation — net-import vs gross-import matters for the calculation
4. Using turnover-£M intensity when the trade body uses tonnes of output — looks naive to investors
5. Claiming market-based emissions reductions from REGOs without checking additionality
6. Excluding red diesel as if it were exempt — it isn't, and HMRC removed the red diesel rebate for most industrial use in April 2022
7. Treating sub-let units on your site as out of scope without documenting the operational-control boundary decision

Trade body context — Make UK

Make UK has issued repeated guidance to UK manufacturers on energy management and SECR. Referencing Make UK's Industrial Decarbonisation roadmap and their annual sector energy survey in your narrative section signals to auditors and investors that you're engaging with industry standards.

The CCC (Climate Change Committee) Industrial Decarbonisation Strategy is the second reference point. Aligning your SECR narrative to the CCC's expected sector trajectory positions you as forward-looking rather than minimum-compliance.