UK Customs Declaration Service (CDS): The Complete Guide for Importers and Exporters

Key Takeaways

• CDS is now mandatory — CHIEF fully closed for imports (September 2022) and exports (June 2024)
• More data required — CDS uses 60+ data elements vs CHIEF’s simpler format
• Real-time tracking — Get instant declaration status updates and notifications
• Integrated payments — Duty deferment, cash accounts, and guarantees in one system
• Procedure codes matter — H1 (standard import), H2 (warehouse), H3 (inward processing), and more

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The Customs Declaration Service (CDS) is now the sole platform for submitting import and export declarations in the United Kingdom. Following the complete decommissioning of the legacy CHIEF (Customs Handling of Import and Export Freight) system, every business moving goods across UK borders must understand how CDS works — whether handling declarations in-house or working with a customs agent.

This guide covers everything UK traders need to know: what changed from CHIEF, how to access CDS, the specific data requirements, common errors to avoid, and practical steps for compliance.

What Is the Customs Declaration Service?

The Customs Declaration Service is HMRC’s modern digital platform for processing customs declarations. Unlike CHIEF, which had been in operation since 1994, CDS was built using contemporary technology and aligns with the EU’s Union Customs Code (UCC) data model.

CDS manages the complete lifecycle of a customs declaration:

• Submission — Initial declaration entry via portal, software, or API
• Validation — Automatic checks against tariff data, licences, and restrictions
• Clearance — Risk assessment and customs checks
• Payment — Duty and VAT calculation with integrated payment options
• Post-clearance — Amendments, audits, and dispute resolution

Why CHIEF Had to Go

CHIEF served UK trade for nearly 30 years, but it faced fundamental limitations:

Issue	Impact
Legacy technology	Built on 1990s architecture; costly to maintain and update
Limited data model	Couldn’t support modern customs requirements or UCC alignment
Brexit complexity	Insufficient flexibility for post-EU customs arrangements
Separate systems	Duty payments, deferments, and guarantees ran on disconnected platforms
End of life	NCTS Phase 5 transition made CHIEF incompatible with EU transit systems

CDS Timeline — When Everything Changed

Understanding the phased transition helps explain why CDS is now the only option:

Phase 1: Northern Ireland (2021)

• 31 October 2021 — All imports from Rest of World to Northern Ireland required CDS
• 31 December 2021 — Full Northern Ireland Protocol implementation

Phase 2: Great Britain Imports (2022)

• 30 September 2022 — CHIEF closed for new import declarations in Great Britain
• November 2023 — Complete switch-off of CHIEF import functionality

Phase 3: Export Transition (2024)

• 4 June 2024 — CHIEF closed for export declarations
• Late 2024 — Full CHIEF decommissioning

Current status: As of 2026, CHIEF no longer exists. All UK customs declarations must use CDS.

Trader Risk Engine (TRE)

From 31 March 2026, the Trader Risk Engine (TRE) became the sole route for customs data submission, replacing the legacy Managing Strategic Suppliers (MSS) system. TRE processes all customs declaration data and provides risk assessments for CDS. This change is automatic and does not require trader action — your CDS submissions are now routed through TRE.

CDS vs CHIEF: Detailed Comparison

Feature	CHIEF	CDS
Data format	SAD (Single Administrative Document)	WCO data model with 60+ data elements
Commodity codes	8-digit acceptable	10-digit required for imports
Procedure codes	7-digit single code	4-digit + up to 99 3-digit codes
Real-time status	Limited visibility	Full tracking and notifications
Post-clearance amendments	Paper-based, slow	Digital self-service
Payment integration	Separate systems	Cash accounts, deferment, guarantees unified
API connectivity	Restricted	Modern REST APIs
Security	Basic authentication	Government Gateway + MFA

Key Data Differences

CDS requires significantly more information than CHIEF:

New or Expanded Requirements:

• Additional procedure codes (second part)
• Comprehensive consignor/consignee details
• Detailed freight and insurance breakdowns
• Specific document references (not just “LIC99”)
• Location of goods and border crossing points
• Guarantees and security references where applicable

Validation Changes:

• CDS validates commodity codes in real-time against the UK Trade Tariff
• Procedure codes must align precisely with intended use
• Prohibitions and restrictions require explicit declaration

How to Access CDS

There are three primary methods for submitting declarations:

1. CDS Exporter/Importer Portal (Free)

HMRC’s web-based portal for businesses making their own declarations.

Best for: Low-volume traders with simple, straightforward imports

Access requirements:

• Government Gateway account
• UK EORI number (GB + 12 digits)
• CDS subscription

Limitations:

• Manual data entry required
• No bulk upload functionality
• Limited integration with business systems
• Not suitable for high volumes

2. Commercial Software

Third-party customs declaration software that connects to CDS via API.

Best for: Regular importers/exporters with established customs processes

Features typically include:

• Address book for regular suppliers/customers
• Template declarations for common shipments
• Integration with ERP and warehouse systems
• Automated validation before submission
• Management reporting and audit trails

Popular providers:

• CustomsWare
• Descartes CustomsInfo
• Agency Manager (ASM)
• iCustoms
• AEB customs software

3. Customs Intermediary

Using a customs broker or freight forwarder to submit declarations on your behalf.

Best for: Businesses without customs expertise or those importing occasionally

What they handle:

• Classification of goods and commodity codes
• Completion of declarations
• Payment of duties and taxes
• Liaison with HMRC on queries
• Post-clearance amendments

Important note: You remain legally responsible for the accuracy of declarations, even when using an agent.

Getting Started: CDS Registration

Before submitting declarations, you must complete these steps:

Step 1: Obtain an EORI Number

All UK businesses trading goods internationally need an Economic Operator Registration and Identification (EORI) number.

Format: GB followed by 12 digits (e.g., GB123456789012)

Application:

• Apply online via HMRC website
• Most VAT-registered businesses receive EORI within hours
• Non-VAT businesses may take 3-5 working days

Step 2: Subscribe to CDS

Log into your Government Gateway account and:

1. Navigate to “Get access to a tax, duty or scheme”
2. Select “Customs Declaration Service”
3. Enter your EORI number
4. Complete the subscription process

Step 3: Set Up Payment Methods

Option A: CDS Cash Account

• Pre-fund account with HMRC
• Duty and VAT deducted at declaration
• Suitable for occasional importers

Option B: Duty Deferment Account

• Defer payment to monthly direct debit
• Requires Customs Comprehensive Guarantee or bank guarantee
• Best for regular importers with cash flow considerations

Step 4: Authorise Your Agent (If Applicable)

If using a customs intermediary:

1. Log into your HMRC account
2. Navigate to “Customs Declare Service”
3. Select “Manage who can access your customs account”
4. Add your agent using their EORI number
5. Set authorisation level (submit declarations, view only, etc.)

Filing Your First Declaration

Whether you use software directly or work through a broker, understanding the filing process helps you verify that declarations are correct.

Step 1: Gather Commercial Documents

You need:

• Commercial invoice showing seller, buyer, goods description, unit prices, total value, currency, and Incoterms
• Packing list showing number of packages, weights, and dimensions
• Certificates and licences where required (origin, health, import licences)

Step 2: Determine the Commodity Code

The commodity code is a 10-digit number classifying your goods for customs purposes:

• Digits 1-6: Harmonized System (HS) code used worldwide
• Digits 7-8: Combined Nomenclature (CN) code
• Digits 9-10: UK-specific Taric codes

Look up codes using HMRC’s Trade Tariff tool at trade-tariff.service.gov.uk. Getting the commodity code right is critical — it determines your duty rate, any import restrictions, and whether you need licences.

Step 3: Calculate the Customs Value

For most imports, this is the transaction value — what you actually paid or will pay. Add costs not included in the invoice price: freight to the UK border, insurance, loading and handling charges, and any royalties or licence fees related to the goods. Do not include UK delivery costs after import or import VAT itself.

Step 4: Determine the Procedure Code

For standard imports into free circulation, use code 40 00 000. If importing goods for inward processing or other special procedures, use the appropriate code (see the Procedure Codes section above).

Step 5: Enter Data into CDS Software

The software guides you through each group of data elements. Double-check the commodity code, customs value, and procedure code — these are the most common sources of errors.

Step 6: Submit the Declaration

Your software sends the declaration to CDS via API. CDS validates the data and returns a response. If accepted, you receive a Unique Consignment Reference (UCR). If rejected, CDS returns an error code explaining what went wrong — fix and resubmit.

Step 7: Pay Duty and VAT

If you have a duty deferment account, charges are added to your monthly statement. If not, you must pay immediately. Postponed VAT Accounting is available for most imports, letting you account for import VAT on your VAT return rather than paying at the border.

Step 8: Keep Records

HMRC requires you to keep customs declaration records for at least four years. This includes the declaration itself, commercial invoices, transport documents, and any certificates or licences.

CDS Declaration Types and Procedure Codes

Every CDS declaration requires a procedure code that defines what’s happening to the goods. Understanding these codes is essential for correct classification.

Procedure Code Structure

CDS uses a different procedure code structure than the legacy CHIEF system. Under CHIEF, procedure codes were seven digits: a two-digit “request” code followed by a five-digit “previous procedure” code (for example, 40 00000 meant “release for free circulation” with no previous procedure).

Under CDS, procedure codes have two parts:

• First part: A four-digit code representing the requested procedure
• Second part: Up to 99 three-digit codes representing additional procedures or previous procedures

For standard imports into free circulation with no special procedures:

• First part: 40 00 (release for free circulation)
• Second part: 000 (no additional procedure)
• Full code: 40 00 000 (compared to 40 00000 in CHIEF)

For inward processing:

• First part: 51 00 (inward processing)
• Second part: varies depending on the specific relief

For temporary admission:

• First part: 53 00 (temporary admission)
• Second part: varies

The three-digit additional codes can indicate:

• 100 — Standard import without special conditions
• 200 — Goods subject to anti-dumping duties
• 300 — Goods under customs warehousing

You can use up to 99 additional codes per item line, which lets you capture complex scenarios where goods are subject to multiple procedures or reliefs simultaneously.

HMRC publishes a full list of CDS procedure codes in the CDS Import and Export Notice on gov.uk. The notice is updated regularly. Software providers typically maintain updated code lists, but verify that your software is current.

Getting the procedure code wrong can have serious consequences. If you use a procedure code for inward processing but don’t actually process and re-export the goods, you may owe back duty plus interest. Always verify the correct procedure code for your situation.

Import Procedure Codes

H1 — Release for Free Circulation

• Standard import where goods enter UK market
• Duty and VAT payable immediately or deferred
• Most common procedure code

H2 — Customs Warehousing

• Goods stored in authorised warehouse
• Duty suspended until removal
• Useful for bulk importers and distributors

H3 — Inward Processing

• Goods imported for processing/manufacturing
• Must be re-exported or placed on market after processing
• Duty relief on import; duty payable if diverted to UK market

H4 — Temporary Admission

• Goods imported temporarily (exhibitions, repairs, events)
• Full duty and VAT relief
• Must be re-exported within specified period

H5 — End-Use Relief

• Reduced or zero duty for specific purposes
• Examples: aircraft parts, research equipment, charity goods
• End-use must be declared and monitored

I1 — Simplified Declaration

• Reduced data at frontier
• Supplementary declaration required within set timeframe
• For authorised traders with simplified procedures

Export Procedure Codes

B1 — Export with outright sale

• Standard export with permanent transfer of ownership
• Most common export procedure

B2 — Export under outward processing

• Goods exported for processing/repair
• Re-imported with duty relief on added value only

Data Requirements for CDS Declarations

A complete CDS import declaration contains 60+ data elements (up to 78 depending on your goods). The key fields include:

The Eight Data Element Groups

CDS data elements are organised into eight groups:

Group 1 — Message Identification includes the declaration type (import or export), the declaration category (standard, simplified, or supplementary), and the unique consignment reference.

Group 2 — Parties and Addresses covers everyone involved in the transaction. You must provide the declarant’s EORI number, the importer’s details, the exporter’s details, and any representatives acting on your behalf.

Group 3 — Totals and Invoicing includes the total number of items, the total invoice value, the currency code, and any discounts or additions to the invoice price.

Group 4 — Transport and Borders covers how the goods are moving and where they enter or leave the UK. You need the mode of transport, the vessel or flight number, the port or airport code, and the expected arrival date.

Group 5 — Goods Location specifies where the goods are physically located at the time of declaration. For imports, this is usually the port of entry.

Group 6 — Goods Identification is the most detailed group. It includes the commodity code (up to 10 digits), the goods description, the net mass in kilograms, the quantity in supplementary units, the country of origin, and any certificates or licences required.

Group 7 — Procedure and Relief covers the customs procedure you’re using, including the procedure code, any special procedures like inward processing or customs warehousing, and any duty reliefs or exemptions.

Group 8 — Additional Information captures document references (such as bill of lading numbers), any previous customs declarations related to the goods, and free-text notes.

Not every declaration needs all 78 elements. A straightforward import of standard goods might use 40-50 elements. Complex shipments involving special procedures, preferential duty rates, or controlled goods will need more. Missing or incorrect data elements are the most common cause of declaration rejections.

Mandatory Core Data

EORI Numbers

• Declarant (agent or business submitting)
• Importer/exporter (if different)

Commodity Codes

• 10-digit codes for imports (from UK Trade Tariff)
• 8-digit codes for exports
• Must be accurate to product specifications

Customs Procedure Codes

• Primary procedure code (4 digits)
• Additional procedure codes (3 digits each)
• Must align with intended goods use

Valuation

• Customs value (transaction value + freight + insurance)
• Currency code (GBP, USD, EUR, etc.)
• Method of valuation (1-6)

Origin

• Country of origin code
• Preference indicator (if claiming trade agreement benefits)
• Evidence of origin where required

Supplementary Data

Transport Information

• Mode of transport at border
• Port of entry/exit
• Carrier details
• Expected arrival/departure

Location and Warehousing

• Location of goods
• Warehouse reference (if applicable)
• Supervising office

Documents and Licences

• Commercial invoice reference
• Packing list
• Import/export licences
• Certificates of origin
• Preference documents (EUR.1, supplier declarations)

Financial Guarantees

• Deferment account number
• Guarantee reference
• Security reference where required

Common CDS Errors and How to Avoid Them

Even experienced traders encounter CDS rejections. Here are the most common issues:

1. Incorrect Commodity Codes

Problem: Using an 8-digit code where 10 digits are required, or misclassifying products.

Impact: Declaration rejected or incorrect duty calculation.

Solution:

• Use the UK Trade Tariff tool for classification
• Consider binding tariff information (BTI) for uncertain classifications
• Consult customs broker for complex products

2. Procedure Code Mismatches

Problem: Import procedure codes used for exports, or vice versa.

Impact: Immediate rejection.

Solution:

• Double-check code before submission
• Maintain reference document with common codes for your products

3. Missing or Incorrect Origin Evidence

Problem: Claiming preferential duty rates without proper documentation.

Impact: Full duty charged; potential penalties.

Solution:

• Obtain EUR.1 movement certificates or supplier declarations
• Ensure origin criteria are met (typically 50%+ originating content)
• Keep evidence for at least 3 years

4. Incomplete Consignor/Consignee Details

Problem: CDS requires full address details where CHIEF accepted minimal information.

Impact: Declaration rejected pending additional data.

Solution:

• Collect complete supplier/customer details
• Maintain accurate address book in customs software

5. Document Reference Errors

Problem: Using “LIC99” (CHIEF convention) instead of specific document references.

Impact: CDS requires explicit declaration of all prohibitions and restrictions.

Solution:

• List specific licence numbers
• Reference relevant certificates and authorisations

6. Incorrect Valuation

Problem: Omitting freight or insurance costs from customs value.

Impact: Underpayment of duty; potential penalties and interest.

Solution:

• Include all costs up to UK border
• Use Incoterms to determine appropriate additions
• Maintain calculation worksheets

CDS Costs and Practical Considerations

Software Costs

If using commercial software:

• Entry-level: £50-200 per month (basic declaration capability)
• Mid-range: £200-500 per month (templates, reporting, some integration)
• Enterprise: £500+ per month (full ERP integration, advanced analytics)

Agent Fees

Customs intermediary charges typically:

• Simple declarations: £25-45 per entry
• Complex declarations: £50-150+ per entry
• Annual contracts: Often include volume discounts

Duty Deferment Costs

• Customs Comprehensive Guarantee: 0% cash cover for established traders
• Bank guarantee: Typically 1-3% of guarantee value annually
• Monthly administration fee: £15-50 per deferment account

Duty Deferment and Payment

CDS integrates with HMRC’s duty deferment scheme, which lets approved traders pay customs duty and import VAT monthly rather than per declaration.

Setting Up Duty Deferment

To use duty deferment, apply for a deferment account using form CDS120. HMRC assesses your creditworthiness and sets a monthly limit based on your typical duty and VAT liability. The limit covers both customs duty and import VAT.

Once approved, you receive a deferment account number. Reference this number in your CDS declarations. When you file a declaration, the duty and VAT are allocated to your deferment account rather than requiring immediate payment.

Monthly Statement and Payment

Each month, HMRC issues a Customs Declaration Statement showing all charges allocated to your account during the previous month. The statement lists each declaration, the duty amount, the VAT amount, and any other charges. You receive the statement around the 6th working day of the month.

Payment is due by the 15th working day of the month. For example, charges accrued in March appear on the statement issued in early April, and payment is due by the 15th working day of April. HMRC collects payment via Direct Debit from your nominated bank account.

Failure to pay deferment charges on time can result in the suspension or revocation of your deferment account. Late payment penalties may also apply.

Postponed VAT Accounting

Postponed VAT Accounting (PVA) is available regardless of whether you have a deferment account. PVA works by recording the import VAT on your CDS declaration. You then include both the import VAT (as input tax) and the corresponding output tax on your VAT return. HMRC provides monthly statements showing all imports where you used Postponed VAT Accounting — you need these for your VAT records.

If you don’t have a deferment account, you must pay duty and VAT for each declaration at the time of filing. Most CDS software integrates with payment systems to facilitate this.

Training Requirements

Staff need training on:

• CDS data requirements and validation
• Commodity code classification
• Procedure code selection
• Documentation standards

Training providers:

• British International Freight Association (BIFA)
• Institute of Export & International Trade
• HMRC webinars and guidance
• Software vendor training programmes

Post-Transition Challenges

Businesses still adapting to CDS face ongoing challenges:

Integration Issues

Connecting existing ERP systems to CDS requires:

• API development or middleware
• Data mapping from internal formats to CDS requirements
• Testing and validation before going live

Timeline: 3-6 months for complex integrations

Data Quality

CDS validates more rigorously than CHIEF. Common quality issues:

• Inconsistent product descriptions
• Outdated supplier/customer records
• Missing preference documentation
• Incorrect units of measurement

Brexit-Related Complexity

Post-EU trade adds layers:

• Rules of origin calculations
• Additional documentation for EU goods
• Divergent UK/EU tariff rates
• Dual NI/GB considerations

Northern Ireland Considerations

The Northern Ireland Protocol creates unique CDS requirements. From 13 April 2026, updated CDS procedures apply to movements between Great Britain and Northern Ireland under the Windsor Framework.

Windsor Framework Updates

GB to NI Movements:

• Goods “not at risk” of entering the EU do not require full customs declarations
• Traders use the UK Internal Market Scheme (UKIMS) to declare goods as not at risk
• Apply for UKIMS authorisation through HMRC

NI to GB Movements:

• Goods moving from Northern Ireland to Great Britain generally do not require import declarations, as Northern Ireland remains part of the UK customs territory for this direction of trade

Rest of World to NI:

• Full CDS declarations are required, just as for imports into Great Britain
• EU customs duties may apply if goods are “at risk” of entering the EU (via the Republic of Ireland)

CDS handles Northern Ireland movements using specific destination codes and procedure codes. When filing declarations for NI movements, you must indicate whether goods are at risk or not at risk, and whether you’re using the UK Internal Market Scheme.

Dual Tariff System

• Green lane: Goods staying in NI — simplified procedures
• Red lane: Goods at risk of entering EU — full customs declarations

Trader Support Service (TSS)

Free service for Northern Ireland traders:

• Completes declarations on behalf of traders
• Helps with goods at risk determinations
• Provides tariff and duty calculation

HMRC publishes detailed guidance on CDS requirements for Northern Ireland movements. The guidance is complex and subject to updates. If you regularly move goods between Great Britain and Northern Ireland, consider specialist advice.

CDS Benefits Beyond Compliance

Despite the transition challenges, CDS offers genuine advantages:

Real-Time Visibility

• Instant declaration status updates
• Email/SMS notifications for clearance, queries, and rejections
• Dashboard view of all declarations and financial positions

Financial Management

• Single view of cash accounts, deferments, and guarantees
• Detailed transaction history
• Easier reconciliation and auditing

Compliance Improvements

• Better audit trails
• Reduced manual errors through validation
• Easier post-clearance amendments
• Enhanced security and fraud prevention

Future-Proofing

• Built to accommodate new trade agreements
• Regular HMRC updates and improvements
• Integration with emerging border technologies

Getting Help with CDS

HMRC Resources

• CDS guidance pages: gov.uk/guidance/customs-declaration-service
• Trade Tariff tool: trade-tariff.service.gov.uk
• Trader support helpline: 0300 322 9434
• Webinars: Regular free sessions on CDS topics

Industry Support

• British International Freight Association (BIFA): bifa.org
• Institute of Export: export.org.uk
• Make UK: makeuk.org
• British Chambers of Commerce: bcc.org.uk

Professional Advice

For complex situations:

• Customs consultants
• Trade lawyers
• Specialist brokers
• Big four accountancy firms (for enterprise scale)

Action Checklist for CDS Compliance

Immediate Actions

• Verify EORI number is active and correct
• Subscribe to CDS via Government Gateway
• Set up payment method (cash account or deferment)
• If using an agent, complete authorisation

System Preparation

• Choose access method (portal, software, or agent)
• If software: complete integration and testing
• Train relevant staff on CDS requirements
• Create internal procedures and documentation

Ongoing Management

• Maintain accurate commodity code database
• Keep supplier/customer details up to date
• Monitor declaration rejections and errors
• Review and optimise processes quarterly

Conclusion

The Customs Declaration Service represents a fundamental modernisation of UK customs infrastructure. While the transition from CHIEF required significant adjustment, CDS provides a more robust, flexible, and internationally aligned platform for managing UK trade declarations.

For most businesses, working with a customs intermediary offers the smoothest path to CDS compliance. For larger traders, investing in compliant software and internal expertise pays dividends in efficiency and control.

The key to CDS success is data accuracy, staff training, and choosing the right access method for your trade volume and complexity. With CHIEF now fully retired, mastering CDS isn’t optional — it’s essential for any UK business trading internationally.

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Last updated: April 2026

For the latest CDS guidance and updates, visit HMRC’s official CDS page