CDS customs declaration – how to read a UK customs entry and what each box means

Every importer into the United Kingdom receives a copy of the customs declaration from their customs broker after clearance — most often as a copy or printout of the declaration data from the agent's software or CDS (printouts often follow the layout of the older paper SAD form, called C88). The problem is that this document, filled with four-digit codes, abbreviations and dozens of numbered boxes, is completely unreadable for most importers. Yet it is precisely in this document that the key information is hidden: what duty was charged and why, which HS code the customs agent applied, whether a tariff preference was claimed, and what the MRN reference number is for tracking the status of the consignment. CDS (Customs Declaration Service) is HMRC's IT system that replaced the old CHIEF system. Understanding the structure of a CDS declaration is not merely an academic exercise — it is a real capability to verify your agent's work, check that duty has been calculated correctly, and react quickly when something goes wrong. In this article we explain step by step how to read every important box of a customs declaration in the CDS system — in plain language for an importer, not a customs officer.

CDS vs CHIEF — why the system changed

Previously the UK processed customs declarations through the CHIEF system (Customs Handling of Import and Export Freight). CDS (Customs Declaration Service) is its successor — a modern platform built on European UCC (Union Customs Code) standards, although the UK post-Brexit implemented its own version based on the UK Global Tariff.

For an importer, the switch from CHIEF to CDS means: - Declaration formats and boxes have changed - The MRN (Movement Reference Number) now has a different format - The process for amending declarations (correcting errors) is different - Importer access to declaration history is via the CDS portal (gov.uk)

If you have older customs documents from before 2023 — they may look slightly different. The guide below covers the current CDS format.

Structure of a customs declaration — general overview

A CDS customs declaration is based on a concept similar to the SAD (Single Administrative Document) — the document used throughout Europe. It consists of:

• The declaration header — general data: importer, customs agent, means of transport, port of entry, total value
• Goods items — each HS code is a separate item with its own duty calculation

After clearance, importers usually receive a copy or printout of the declaration data from their agent's software or CDS (older paper SAD forms were called C88).

Key CDS declaration boxes — explained

CDS itself works with numbered data elements (DE x/y). The "box" numbers below come from the paper SAD/C88 layout that many entry printouts still follow; the matching CDS data element is shown in brackets.

DE 1/1 and DE 1/2 — Declaration Type

This consists of two parts: - DE 1/1 (Declaration Type): IM = import, EX = export, CO = trade with special fiscal territories / within a customs union - DE 1/2 (Additional Declaration Type): A = standard declaration, B = occasional simplified, C = simplified with authorisation, D/E/F = the pre-lodged equivalents of A/B/C, Y/Z = supplementary declarations

Example: IM A = standard import declaration. Most importers will see exactly this code.

Box 8 (CDS: DE 3/15–3/16) — Importer (Consignee / Declarant)

The importer's EORI number in the format GB + 12 digits (e.g. GB123456789000). This box verifies that the customs agent has used the company's correct EORI number. An error in the EORI can lead to problems with import VAT and the ability to reclaim it.

Box 14 (CDS: DE 3/17–3/21) — Customs agent (Declarant / Agent)

The customs agent's EORI number. This confirms who lodged the declaration. In the UK a customs agent may act as: - Direct Representative — acts on behalf of the importer; the importer bears liability - Indirect Representative — the agent is jointly and severally liable with the importer for customs debt

Most customs agents in the UK act as Direct Representatives.

Box 22 (CDS: DE 4/11 and DE 4/14) — Currency and invoice value

Format: ISO currency code + value (e.g. PLN 45000.00). This is the commercial invoice value — the starting point for calculating the customs value.

Important: Customs value ≠ invoice value. The customs value includes the cost of transport and insurance to the UK border (under CIF or equivalent Incoterms). Under EXW or FOB Incoterms, the customs agent adds the cost of sea/air/road freight and insurance.

DE 6/14 and DE 6/15 — Commodity Code

This is one of the most important fields. In CDS the commodity code is declared in two data elements: DE 6/14 — the first 8 digits (Combined Nomenclature code), and DE 6/15 — digits 9 and 10 (TARIC code). Together they give the 10-digit commodity code from the UK Trade Tariff.

How to verify the HS code: 1. Go to trade-tariff.service.gov.uk 2. Enter the code from DE 6/14 and DE 6/15 3. Check the goods description, duty rate and preference conditions 4. Compare with your goods description

If the HS code does not match your goods — this may be an error by the customs agent requiring correction or a voluntary disclosure.

Box 36 (CDS: DE 4/17) — Tariff Preference

A code indicating whether a preferential duty rate has been applied: - 100 = no preference (MFN rate — Most Favoured Nation, i.e. the standard UK Global Tariff rate) - 300 = preference under a trade agreement (e.g. TCA with the EU — Trade and Cooperation Agreement) - 200 = DCTS preference (Developing Countries Trading Scheme — formerly GSP) - 400 = non-imposition of customs duties under a customs union (EU agreements with Turkey — per Appendix 12 to DE 4/17)

If you are importing goods of Polish (EU) origin and you see code 100 in Box 36 instead of 300 — this means the customs agent has not applied the TCA preference. This may have been due to a missing proof of origin document or an agent error. In that case you can submit a C285 claim for a refund of overpaid duty.

Box 37 (CDS: DE 1/10 and DE 1/11) — Customs Procedure Code

In CDS this is a four-digit procedure code in DE 1/10, declared together with a three-character additional procedure code in DE 1/11 (000 where no other additional procedure code applies). It indicates the customs procedure applied to the goods. The first two digits are the requested procedure (what happens to the goods after clearance); the next two are the previous procedure (where the goods come from — what customs status they held).

The most important procedure codes for imports:

Code	Procedure
40 00	Release for Free Circulation — goods are imported from a third country and enter the UK market
42 00	Release for free circulation with simultaneous VAT-exempt onward supply to an EU Member State (onward supply relief; in the UK used only for goods moving into Northern Ireland)
61 10	Re-importation in an unaltered state with release for free circulation, claiming Returned Goods Relief (goods previously exported from the UK, returning)
51 00	Suspensive procedure (Inward Processing Relief)
53 00	Temporary Admission (Temporary Admission / ATA Carnet analogue)
71 00	Customs Warehouse — goods under customs supervision

Example: You are importing furniture from Poland to the UK. The procedure code should be 40 00 (release for free circulation). If you see 51 00 — something has gone wrong; the goods are under inward processing instead of standard import.

Box 41 (CDS: DE 6/2) — Supplementary Unit

Some HS codes require an additional unit of measure alongside weight (e.g. for alcohol — litres of pure alcohol; for medicines — DDD doses; for electronics — pieces). Box 41 contains the quantity in that unit. If the customs agent has entered an incorrect quantity — this may affect the accuracy of any excise duty or special charges calculated.

Box 44 (CDS: DE 2/3) — Documents Produced

A list of all documents attached to the customs declaration, in the format: document code + reference number.

Example document codes: - U116 = statement on origin under the EU–UK TCA (Article 56(4)(a); EUR.1 is not used in UK–EU trade); U117 = importer's knowledge (Article 58 TCA) - N380 = Commercial invoice - N730 / N705 / N740 = Road consignment note (CMR) / bill of lading / air waybill - Y900 = Declared goods are not covered by CITES

If you claimed a tariff preference (Box 36 = 300) but do not see code U116 or U117 in Box 44 — this is a red flag. It means the tariff preference is not supported by a document, which could result in HMRC withdrawing it.

Box 47 (CDS: DE 4/3–4/8) — Tax Lines (duty and tax calculation)

This is the most important box for an importer from a financial perspective. It contains a breakdown of all charges due:

Column	Description
Tax Type	Type of charge: A00 = customs duty; B00 = import VAT; A30 / A35 = definitive / provisional anti-dumping duty
Tax Base	The taxable base (customs value for duty; customs value + duty for VAT)
Rate	Percentage rate
Amount	Amount in GBP
Method of Payment	Payment method: E = deferred payment (duty deferment account); A = immediate payment in cash; P = immediate payment from the CDS cash account

How to check whether duty is correct: 1. Take the value from Box 22 (invoice value) 2. Add transport and insurance costs to the UK border (CIF value) 3. This is the customs value 4. Multiply by the duty rate for the commodity code in DE 6/14–6/15 5. Compare with the A00 amount in Box 47

If the figures do not match — check whether the customs value in the declaration is correct and consult your customs agent.

MRN — where to find it and what it is used for

The MRN (Movement Reference Number) is the unique identifier for each customs declaration in the CDS system. The UK format is 18 characters (e.g. 26GB123456789ABCDE5). Where to find it:

• On the copy or printout of the declaration from your customs agent — usually in the header
• In the confirmation from your customs agent (email with the MRN)
• In the CDS portal (for importers registered in the system)

What the MRN is used for: - Tracking clearance status in the CDS system - Reference when contacting HMRC - Reference number in correspondence relating to that declaration - Basis for submitting an amendment or a C285 claim (duty repayment)

How to check the status of a declaration in CDS

Importers registered in the Customs Declaration Service (via Government Gateway) can check the status of their declarations online. The status can be:

Status	Meaning
Accepted	Declaration accepted by the system; goods may be released
Cleared	Clearance complete; goods released
Held	Declaration on hold — awaiting documents or an HMRC decision
Rejected	Declaration rejected — data error; must be corrected and resubmitted
Invalidated	Declaration cancelled (by the customs agent or HMRC)

How to correct an error in CDS after clearance — amendment vs re-declaration

After clearance is complete, the importer or customs agent may identify an error in the declaration. Depending on the nature of the error:

Amendment

For minor formal errors — a typo in the description, an incorrect quantity in Box 41, a missing document reference in Box 44. Until the declaration has cleared and the final tax calculation message has been received, the agent can amend it in their CDS software. Once the declaration has cleared, it can no longer be amended in the software — you need to contact HMRC, which will review the request. Post-clearance amendments can be requested up to 3 years from when the declaration is accepted or a control is applied to the goods, whichever is earliest.

Important: A post-clearance amendment that results in additional duty (e.g. correcting the HS code to one with a higher rate) requires an application for a voluntary clearance amendment (underpayment) (C2001); one that results in an overpayment requires a C285 repayment claim. HMRC may charge interest on the difference; whether a penalty applies depends on the circumstances, so confirm the details with HMRC or your customs agent.

Re-declaration (cancel and resubmit)

Cancelling and resubmitting a declaration in CDS software is only possible while the declaration has not yet cleared. After clearance, cancellation requires a request to HMRC and is only possible within 90 days from when the declaration is accepted or a control is applied to the goods, whichever is earliest.