Key Takeaways
- Zero customs duty applies to 33 specific industrial goods imported for offshore wind manufacturing from 1 April 2026
- Authorised use procedure requires prior HMRC approval — traders must apply and receive authorisation before using the relief
- Conditional relief: goods must be used for offshore wind manufacturing within a set period or back-duties become payable
- Eligible goods include cables, rotors, rotor blades, auxiliary systems, and low-voltage systems for turbines and substations
- Estimated savings of millions of pounds annually for UK manufacturers following record £22bn offshore wind investment
- Implementation date is 1 April 2026 under The Customs (Tariff and Miscellaneous Amendments) (No. 2) Regulations 2026 (SI 2026/253)
Overview: New Duty Relief for Offshore Wind Sector
The UK government has introduced a new authorised use measure removing customs duty on 33 industrial goods used in offshore wind manufacturing, effective 1 April 2026. The measure forms part of broader support for the renewable energy sector following record investment secured in January 2026’s Contracts for Difference Allocation Round 7, which attracted 8.4GW of capacity and £22 billion of investment.
Under The Customs (Tariff and Miscellaneous Amendments) (No. 2) Regulations 2026 (SI 2026/253), eligible imports receive zero customs duty at the border when used for specified offshore wind manufacturing purposes. The relief applies to components including cables, rotors, rotor blades, and auxiliary systems used in both onshore and offshore substations or wind turbines.
This is not an automatic exemption. Importers must secure prior HMRC authorisation under the special procedure for authorised use (end-use). Failure to use the goods for their specified purpose within the required timeframe triggers liability for back-duties at the standard import duty rate — either 2% or 6% depending on the commodity code.
The measure updates the Authorised Use Document to version 2.23 (dated 3 March 2026) and the Authorised Use Rates Document to version 1.23, replacing the previous versions dated 26 November 2025. Most provisions take effect from 1 April 2026.
What Is Authorised Use?
Authorised use (formerly known as end-use) is a special customs procedure that allows traders to import goods at a reduced or zero rate of duty, conditional on the goods being used for a specific purpose within a set period. The procedure is governed by the Taxation (Cross-border Trade) Act 2018 and detailed in HMRC’s Authorised Use Document.
How the Procedure Works
The authorised use process operates as follows:
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Application: Before importing the goods, the trader applies to HMRC for authorisation, specifying the commodity codes, intended use, and processing timeline.
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Authorisation grant: HMRC reviews the application and, if satisfied, issues an authorisation reference number. This must be declared on the customs declaration at import.
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Import at zero rate: Goods are declared under the authorised use procedure with the appropriate commodity code and relief indicator. No customs duty is payable at the border.
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Use within specified period: The importer must use the goods for the specified purpose (offshore wind manufacturing) within the timeframe set in the authorisation — typically the standard authorised use period unless otherwise specified.
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Discharge: Once the goods have been used for their specified purpose, the authorisation is discharged. HMRC may require evidence of use.
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Compliance checks: HMRC maintains the right to audit records and verify that goods were used as declared. Failure to comply triggers back-duty liability.
Legal Basis
The legal framework for this specific offshore wind relief is established in SI 2026/253, which amends the UK Global Tariff to introduce zero duty rates for the 33 specified commodity codes when imported under authorised use for offshore wind manufacturing. The legislation came into force on 1 April 2026 under regulation 1(2)(c) of the statutory instrument.
HMRC’s guidance on special procedures confirms that authorised use is a suspensive arrangement — duty liability is suspended at import and only becomes permanent once the goods are used for their authorised purpose. If goods are diverted to other uses or re-exported without processing, different rules apply.
Eligible Goods: The 33 Commodity Codes
The duty relief applies to exactly 33 industrial goods, identified by their CN10 commodity codes. The full list appears in the Authorised Use Rates Document version 1.23 and was announced in the government’s 10 March 2026 press release. The eligible goods fall into four broad categories:
Cables and Electrical Systems
- High-voltage submarine cables for offshore wind farm connections
- Inter-array cables connecting individual turbines
- Export cables transmitting power to shore
- Low-voltage control and monitoring cables
- Fibre optic cables for turbine communication systems
Rotor Components
- Complete rotor assemblies for wind turbines
- Rotor blades (individual blades and blade sets)
- Rotor hubs and blade bearings
- Pitch systems and blade adjustment mechanisms
Auxiliary Systems
- Cooling systems for turbine generators
- Hydraulic systems for blade pitch control
- Lubrication systems for gearboxes and bearings
- Fire suppression systems for nacelles
Substation Equipment
- Transformers for offshore substations
- Switchgear and circuit breakers
- Control and protection systems
- Low-voltage distribution panels
Duty Rates Removed
The 33 commodity codes previously carried customs duty rates of either 2% or 6% under the UK Global Tariff. The new measure reduces these to zero when imported under authorised use for offshore wind manufacturing. Standard third-country duty rates continue to apply if the goods are imported without authorised use authorisation or used for other purposes.
For traders unsure about the correct commodity code for their goods, the HMRC Integrated Online Tariff provides the definitive classification. Using the correct code is critical — an incorrect code may mean the goods are not covered by the relief, or worse, could trigger a compliance investigation.
How to Apply for Authorised Use Authorisation
Traders must secure HMRC authorisation before importing goods under the offshore wind duty relief. The application process follows the standard authorised use procedure with some sector-specific considerations.
Step 1: Determine Eligibility
Before applying, confirm that:
- The goods you intend to import are among the 33 eligible commodity codes
- The goods will be used for offshore wind manufacturing (including both onshore manufacturing of offshore wind components and offshore installation)
- Your organisation has the operational capacity to use the goods as declared
- You can maintain the records required for compliance
Step 2: Prepare Application Documentation
HMRC requires the following information for authorised use applications:
- Commodity codes: Full CN10 codes for all goods to be imported under the authorisation
- Intended use: Detailed description of how the goods will be used in offshore wind manufacturing
- Processing timeline: Expected timeframe from import to use (the standard authorised use period applies unless variation is requested)
- Quantities: Estimated annual import volumes for each commodity code
- Business details: EORI number, registered address, and primary contact
- Premises information: Locations where goods will be stored and processed
Step 3: Submit Application
Applications are submitted through the Customs Declaration Service (CDS). The application form requires:
- Applicant details and EORI number
- Commodity code list with descriptions
- Declaration of intended use
- Statement of compliance capability
HMRC typically processes authorised use applications within 30 days, though complex applications may take longer. It is advisable to apply well in advance of planned imports.
Step 4: Receive Authorisation Reference
Upon approval, HMRC issues an authorisation reference number. This reference must be:
- Declared on all customs declarations for goods imported under the relief
- Kept on file with supporting documentation
- Provided to any customs agents acting on your behalf
Step 5: Import Declarations
When importing goods under the authorised use relief, the customs declaration must include:
- The correct CN10 commodity code
- The authorised use procedure code
- Your authorisation reference number
- The correct duty relief indicator
Using a customs broker or freight forwarder experienced in authorised use procedures is recommended, particularly for high-value shipments where classification errors could be costly.
Conditions and Compliance Requirements
Authorised use is a conditional relief. Importers must meet ongoing compliance obligations or face back-duty liability and potential penalties.
Use Within Specified Period
Goods imported under authorised use must be used for their specified purpose within the timeframe set in the authorisation. The standard period is typically measured from the date of import. If goods are not used within this period, they must either be:
- Re-exported outside the UK
- Destroyed under customs supervision
- Declared to free circulation with payment of outstanding duty
Failure to meet the timeframe without taking one of these actions triggers automatic duty liability at the standard rate.
Record-Keeping Requirements
Authorisation holders must maintain records demonstrating compliance. HMRC specifies the following minimum requirements:
- Import records: Customs declarations, commercial invoices, and transport documents for all goods imported under the authorisation
- Usage records: Production records, installation logs, or other evidence showing goods were used for offshore wind manufacturing
- Stock records: Systems to track goods from import through to use, preventing unauthorised diversion
- Disposal records: Documentation for any goods re-exported, destroyed, or otherwise disposed of
Records must be kept for at least four years from the date of import and made available to HMRC on request.
Compliance Audits
HMRC conducts compliance checks on authorised use authorisations. These may include:
- Document reviews to verify records are complete and accurate
- Site visits to inspect goods and storage facilities
- Interviews with staff responsible for customs compliance
- Reconciliation of import quantities with usage records
Cooperation with audits is mandatory. Failure to provide requested information may result in suspension or revocation of the authorisation.
Back-Duty Liability
If goods are not used for their authorised purpose, or if compliance conditions are breached, the importer becomes liable for:
- Customs duty at the standard rate (2% or 6% depending on commodity code)
- Interest on unpaid duty from the date of import
- Potential penalties for negligent or deliberate non-compliance
The liability falls on the authorisation holder, even if goods were transferred to a third party without proper customs procedures.
Transfer of Goods
Goods imported under authorised use may only be transferred to another party if:
- The transferee holds their own authorised use authorisation covering the same goods and purpose
- The transfer is declared to HMRC using the appropriate customs procedure
- Records are updated to reflect the transfer
Unauthorised transfers constitute a breach of the authorised use conditions and trigger back-duty liability.
Financial Impact and Sector Context
The new duty relief measure is estimated to save UK manufacturers “millions of pounds a year” according to the government’s 10 March 2026 announcement. While precise figures depend on import volumes, the savings are significant for a sector that has just secured record investment.
Investment Context
The duty relief follows the January 2026 Contracts for Difference Allocation Round 7 results, which awarded 8.4GW of offshore wind capacity at £22 billion of investment. This represents the largest single round of offshore wind awards in UK history and signals strong sector growth over the coming decade.
Manufacturers supplying components for these projects will benefit directly from the duty relief. A typical offshore wind farm requires substantial quantities of cables, rotors, and auxiliary systems — all now eligible for zero duty when imported under authorised use.
Illustrative Savings
Consider a manufacturer importing rotor blade assemblies valued at £10 million annually. At the previous 2% duty rate, this would incur £200,000 in customs duty. Under the new measure, this duty is eliminated, improving project economics and potentially reducing costs for offshore wind developers.
For high-voltage submarine cables, which may carry 6% duty, the savings are proportionally larger. A £50 million cable import would previously have incurred £3 million in duty — now zero under authorised use.
Competitive Positioning
The relief strengthens the competitive position of UK-based manufacturers against European competitors. Several EU member states offer similar duty reliefs for renewable energy components, and the UK measure ensures British manufacturers are not disadvantaged.
For companies considering where to locate offshore wind manufacturing capacity, the duty relief is one factor among many — but for import-dependent operations, it materially improves the UK’s cost proposition.
Frequently Asked Questions
Does the duty relief apply to onshore wind projects?
No. The authorised use relief is specific to offshore wind manufacturing. Goods used for onshore wind projects do not qualify unless they are also used in offshore wind manufacturing. The commodity codes and authorised use purpose are explicitly defined for offshore applications.
Can I import goods before receiving authorisation?
No. Authorisation must be in place before goods are imported under the relief. Imports made without authorisation are subject to standard duty rates. Retroactive authorisation is not available.
What happens if my offshore wind project is cancelled?
If goods imported under authorised use cannot be used for their specified purpose due to project cancellation, you must either re-export the goods, destroy them under customs supervision, or declare them to free circulation with payment of outstanding duty. Failure to take one of these actions triggers back-duty liability.
Can multiple companies share a single authorisation?
No. Each company must hold its own authorised use authorisation. However, a parent company with multiple subsidiaries may apply for a single authorisation covering all entities, provided they are all named in the application and meet compliance requirements.
How long does authorisation last?
Authorised use authorisations do not have a fixed expiry date but remain valid as long as the holder continues to import goods under the procedure and meets compliance obligations. HMRC may review authorisations periodically and can revoke them for non-compliance.
Is the relief available for goods imported from the EU?
Yes. The authorised use relief applies to goods imported from any country outside the UK, including EU member states. Post-Brexit, EU-UK trade is subject to customs procedures, and the authorised use relief operates independently of the UK-EU Trade and Cooperation Agreement.
What if I’m unsure about the correct commodity code?
Use the HMRC Integrated Online Tariff to verify the correct code. For complex classifications, consider applying for a Binding Tariff Information (BTI) ruling, which provides legal certainty on the correct code for your goods. Using an incorrect code may mean the goods are not covered by the relief.
This article covers the authorised use duty relief for offshore wind components effective 1 April 2026. For commodity code classification assistance, tools like TariffFlow can help verify the correct code and maintain audit-ready records of your classification decisions.