Authorised Use procedure in the UK — the little-known way to lower duty

Authorised use (AU), also known as end-use relief or the end-use procedure, is a UK customs procedure that allows goods to be imported at a reduced or zero duty rate, provided the goods stay in the UK and are consumed in a strictly defined, authorised purpose. The most common cases are civil aviation parts (usually 0% duty subject to fitting in an airworthy aircraft), marine parts for commercial vessels, raw materials for food production, and pharmaceuticals. Legal basis: UCC art. 254, UK Taxation (Cross-border Trade) Act 2018 and HMRC Notice 3001 (special procedures).

This article is a spoke in the UK customs reliefs cluster — you'll find the hub of all special procedures in UK customs reliefs for importers — the complete guide to special procedures. Related foundations: UK customs value (because under AU you still declare the full customs value), Importer of Record (responsible for meeting the end-use condition), PVA.

What authorised use (AU) means in practice

AU is a mechanism where HMRC allows lower duty (or 0%) in exchange for your commitment that the imported goods will be consumed in line with the purpose defined in the trade tariff. The goods enter UK free circulation — unlike IPR, where they stay under customs supervision until re-export. But entry into free circulation is conditional: until you document the end-use, HMRC treats the declaration as open.

Three classic scenarios the EasyClearance Team sees most often with clients:

• Aviation parts importer — brings in turbine blades from the USA for a Rolls-Royce engine used on a BA aircraft. Standard duty 2.7%, under AU: 0% (footnote CR008 — civil aircraft end-use). Annual savings: £120,000-£400,000 depending on volume.
• Food production — imports raw cane sugar from Brazil for a UK refinery under CN code 1701 13. Standard duty: £339 per 1,000 kg. Under AU into a food refinery: preferential tariff quotas plus end-use reduction.
• Marine engine rebuilder — brings in pistons, crankshafts, injectors for commercial ship engines. Chapter 8409 — many codes have an AU footnote as "for commercial shipping vessels".

How to check whether my CN code has an AU rate

Open the UK Integrated Online Tariff and type in your 10-digit CN code. If an AU rate exists for that heading, you'll see a separate row tagged End-use or Authorised use, usually at a lower duty rate or 0%. Below, you'll find a footnote (e.g. CR008, CD624) defining the end-use condition. Click the footnote — it expands into a detailed description of which uses qualify, which records you must keep, and which exclusions apply.

If there's no separate End-use row, your code doesn't have an AU rate. In that case, check whether you might fit another special procedure (IPR for re-export, outward processing for goods sent away for processing) or special tariff quotas.

AU vs Inward Processing Relief — the crucial difference

This is the most common importer mix-up. Both regimes reduce duty, both require HMRC authorisation, both require record-keeping — but they have entirely different economic purposes.

One practical situation bridges both regimes: transfer of rights and obligations (TORO). Importer A brings in a component under AU and then sells it to a contract manufacturer B, who uses it under IPR to assemble an exported product. TORO lets you hand over the obligations between authorisations without creating a customs debt — but it requires both SP3 authorisations to cover it in advance.

HMRC authorisation process — step by step

Full AU authorisation in the UK runs through the SP3 (Special Procedures application) form. The typical flow we see with EC clients:

1. Pre-application review (1-2 weeks) — you identify every CN code you want AU to cover, verify the footnotes, estimate the annual volume and value, map the locations (warehouse, production site), define the end-use process and identify the point of discharge (the moment the end-use condition is met — e.g. installation in an aircraft, completion of sugar refining).
2. SP3 submission — you submit the application via the gov.uk portal. Required documents: EORI, description of the planned activity, scale, locations, evidence of bookkeeping capability (sample from stock system), compliance history (C79 VAT and CDS audit trail for the last 2 years).
3. HMRC triage (2-4 weeks) — HMRC assigns a case officer, asks for additional information, and often requests a pre-authorisation site visit.
4. Pre-authorisation audit (1-3 days on-site) — HMRC checks: whether the stock system links import to production, whether you have an audit trail at unit level, whether the end-use processes match those declared, whether physical safeguards prevent goods leaking out of the procedure.
5. Decision (2-6 weeks after the audit) — authorisation issued, refused, or conditional (e.g. with a requirement to fix gaps in the stock system). Typical overall timeline: 6-12 weeks from SP3 submission for simple cases; 4-6 months for multi-site enterprise set-ups.
6. First import under AU — on CDS you use the properly configured procedure code (usually 44 00) plus the additional procedure code identifying AU. The authorisation number appears in Data Element 2/3 on the declaration.

Authorisation by declaration — the fast lane for small volumes

For importers who don't want (or need) a full SP3 authorisation, there's a shortcut: authorisation by customs declaration. You declare AU directly on the CDS at a specific import, without prior authorisation. Conditions:

• No more than 3 imports under AU in any 12-month window.
• Value of a single import ≤ £500,000.
• Does not apply to sensitive categories (e.g. certain agricultural products).
• The 4-year record-keeping rule applies identically to full authorisation.
• HMRC can audit post-clearance — so the paperwork has to be ready before you submit the declaration.

In EC practice: if a client does ≥4 imports/year or a total value ≥£1.5m/year, full SP3 authorisation is cheaper. Each authorisation by declaration carries its own audit risk, whereas SP3 gives you a single defined commitment for the authorisation period (usually 3 years with renewal).

Record-keeping — what HMRC wants to see in an audit

HMRC audits AU more often than standard imports — on average once every 18 months for active authorisations. The reason is the risk of "diversion" — a situation where AU goods are redirected to a use other than the authorised one (e.g. an aviation part sold into the used-parts market instead of being fitted to an aircraft).

Mandatory documentation (4 years from discharge of the procedure)

1. Import declaration (CDS MRN, C88 for legacy) with the AU procedure code and authorisation number.
2. Commercial invoice, packing list, bill of lading / AWB.
3. Stock register — a chronological record of every AU import, with fields: MRN, date, CN code, quantity, customs value, storage location, status (in warehouse / in production / consumed).
4. Bill of materials (BoM) linking each AU import to a specific production or installation work order.
5. Proof of end-use — e.g. a work order with installation date and engineer's signature, a certificate of installation in an aircraft (EASA Form 1 or FAA 8130-3), a production report with date and volume.
6. Scrap / waste documentation — if the process produces waste from the original import, you must record quantity, value and disposal method (scrap usually requires a diversion declaration and proportional duty payment).
7. TORO documentation — if you've transferred obligations to another authorised holder.

The most common mistakes and risks

From our work with AU clients we see recurring points of failure:

• Assuming AU works "retrospectively" — that you can file a standard import at full duty and then top up the lower rate. You can't. AU has to be declared on the import declaration. Retrospective authorisation is possible, but only exceptionally, and HMRC rarely agrees.
• No stock system with MRN matching — firms that run stock in Excel usually lose their authorisation at an AU audit. HMRC requires an ERP/WMS system with a unit-level audit trail.
• Diversion without paying duty — a client under AU sold "surplus" parts to a broker instead of fitting them. That is diversion — you have to submit a diversion declaration and pay full duty + VAT + interest + a potential penalty.
• Incorrect classification — a CN code with no AU footnote doesn't qualify, even if "similar" goods have an AU rate. Always verify the specific 10-digit CN. Helpful: HS code — how to find and verify.
• Mixing AU up with IPR — the importer declares AU but actually re-exports the finished product. HMRC reclassifies it as IPR and demands IPR documentation (which isn't there), which ends in full duty payment.
• No TORO when selling a semi-finished product — if under AU you import a component and then sell it (as a component, not a finished product) to another firm, that firm must have its own AU authorisation or there must be a TORO transfer. Otherwise it's diversion.

Is AU worth it for me — a decision framework

The EC team uses this quick heuristic before a full compliance audit:

1. Step 1 — tariff check: does my 10-digit CN code have an End-use footnote in the trade tariff? NO → AU doesn't apply, look for another relief.
2. Step 2 — eligible use: does my end-use fit the footnote description exactly? Fitting in an airworthy civil aircraft ≠ selling to a spare-parts broker. Food production ≠ refining for a non-food purpose.
3. Step 3 — volume: does the annual duty saving beat the authorisation + administration cost (HMRC fees are 0 for AU, but the internal compliance + audit cost = ~£3,000-£15,000/year)? Break-even is usually at ~£10,000/year of duty saving.
4. Step 4 — compliance capacity: do I have a stock system with an MRN-level audit trail? Do I have someone responsible for monthly reconciliation? Is the compliance history (last 2 years VAT + CDS) clean?
5. Step 5 — long-term fit: are supplier and customer contracts stable enough that a 3-year authorisation pays off? Are you planning to extend into IPR or a customs warehouse in the same period?

If four of the five answers are YES, AU is probably worthwhile and the EC team recommends a full SP3 authorisation. If it's two or fewer, consider authorisation by declaration for ad-hoc imports or stick with the standard regime.

Frequently asked questions about authorised use UK

Can I use AU on car parts?

Usually not. Civil car parts as a rule don't have an AU footnote in the UK trade tariff — the standard duties in chapter 87 apply normally. Exceptions: parts for specialist military vehicles (different regime), emergency vehicles (rarely, case-by-case). For imported cars, look instead at the standard vehicle import procedure.

Does AU also apply to imports from Poland after Brexit?

Yes. Since Brexit, importing from the EU (including Poland) into the UK is a full customs import. AU works the same way for imports from PL, DE, FR as it does for USA or China. Provided the CN code has an AU footnote and your use qualifies.

If I have AU, do I still need to declare the full customs value?

Yes. AU changes the duty rate, not the basis. You declare the customs value in line with Methods 1-6 (more: UK customs value — 6 methods) — the AU rate is applied to that calculated value.

Does HMRC charge a fee for SP3 authorisation?

No. Submitting the SP3 and obtaining authorisation are free. The costs are solely your preparation time, any consulting, and the ongoing compliance (stock system, monthly reconciliation, audit readiness).

What should I do if I change production site or supplier?

Changes to the scope of authorisation (new location, new CN code, change in the end-use process) require an authorisation amendment via HMRC — a separate SP3A form. You must not import under AU into an undeclared location; HMRC spots that immediately at audit by reconciling the delivery address with the addresses on the authorisation.

Does Northern Ireland have special AU rules?

Yes. NI operates under the Windsor Framework — AU for goods imported into NI (or moved GB→NI) applies EU UCC rules plus additional NI conditions. If you trade to/from NI, the authorisation must be coordinated with the HMRC NI team and requires a separate set-up.

Does AU apply only to B2B, or also to B2C?

Formally, AU is open to any importer, but in practice it's a B2B regime. Consumers don't meet the 4-year record-keeping demands, don't have stock systems and rarely cross the profitability threshold (minimum ~£10,000 annual saving). For B2C the EC experts recommend the standard import at full duty.

Want to check whether your import qualifies for AU?

The EasyClearance Team runs compliance audits for clients on CN codes carrying end-use footnotes — we verify eligibility, estimate the annual duty saving and prepare the SP3 with pre-authorisation audit readiness. Average saving among AU clients: £80,000-£500,000 per year.

chatWhatsApp +44 7404 091 503 callHelpline +44 7404 091503 Request an AU audit

What next — related articles

• UK customs reliefs for importers — special-procedures hub (atomic)
• UK customs value — the 6 valuation methods (Method 1-6)
• Importer of Record UK — who is responsible for valuation and end-use
• HS code — how to find and verify (ISZTAR + HMRC)
• Postponed VAT Accounting (PVA) — how it works in the UK
• CDS authorisations — what you need from a customs agent

Disclaimer: This article is informational and does not constitute legal, tax or binding HMRC advice. AU eligibility depends on the specific CN code, the end-use and your business's circumstances. Before applying for SP3, check the trade tariff and HMRC Notice 3001. For a binding interpretation, apply for an Advance Tariff Ruling (ATaR) or contact the HMRC AEO & Authorisations team.