Published:
18 December 2021
Updated:
15 May 2025
Contents
Actions you need to take
- Using the Trader Support Service (TSS), you will have already generated the declarations required to send your goods from Great Britain (GB) to Northern Ireland (NI). Your goods have since been successfully delivered to NI. (No action required)
- TSS generates a Supplementary Declaration using data you already submitted for the Entry Summary Declaration. (No action required)
- Full data sets (see details on next page) are required for completion to close the customs journey and pay any duties and other charges. (Active step)
- Submission of the Supplementary Declaration in TSS is required by the tenth calendar day of the month following the goods movement. (Active step)
- If you declare that the goods are ‘not at risk’, maintain evidence of the movement to demonstrate that goods are ‘not at risk’ (see section on right). (Active step)
- If your goods are ‘at risk’, pay any duty requested by TSS or claim a waiver if eligible. For further help refer to the Tariffs on goods movements into Northern Ireland (NI) guide. (Active step)
Next steps for completing Supplementary Declarations
- Capture required data – see following sections
- Confirm your commodity codes
Options to manage duty liability
- Determine if your goods are of preferential origin
- Ensure you are authorised under the UK Internal Market Scheme to declare your goods are ‘not at risk’ (see Moving goods you bring into Northern Ireland as ‘not at risk’ of moving to the EU on GOV.UK for further details)
- Refer to the Tariffs on goods movements into NI guide for step-by-step instructions on options to minimise your tariff exposure
What is ‘at risk’?
- ‘At risk’: Applies to goods that enter NI but may later be sold or consumed within the European Union (EU)
- ‘Not at risk’: Applies to goods that will be for sale to or final use by end-consumers located in the UK
Claiming a waiver
If your imports fall into the ‘at risk’ category and duty is payable, you may be eligible to claim a waiver for this duty. Refer to How to claim a customs duty waiver guide on NICTA for more information.
If you encounter errors in TSS, the Guidance on resolution to common error codes for Supplementary and Full Frontier Declarations on NICTA will help you resolve these.
Data requirements for Supplementary Declarations – Consignment Data
Mandatory
- Goods Domestic status
- Which type of declaration do you intend to make?
- Any procedure(s) not currently supported by TSS?
- Importer EORI must be correct and per agreed Incoterms. Note: for a GB EORI, the importer name and address is required to complete the declaration
- Exporter EORI must be correct
- Type of Movement
- Destination Country
- Incoterm
- Location of Goods
- Delivery Location Country/Town
- Use Postponed VAT Accounting (PVA)?
- Header Previous Document / Previous Document Reference
- Holder of authorisation
Mandatory under certain conditions
- VAT number (for PVA)
- Header Additions and Deductions
- Freight charges & currency
- Insurance Charges & Currency
- VAT Adjustment & Currency
- Warehouse Identifier
- Supervising Customs Office
Data requirements for Supplementary Declarations – Item data
Mandatory
- Commodity Code
- Country of Origin
- NI Additional Information Codes
- Preference Code
- Additional Procedure Code
- Procedure Code
- Goods Description
- Item Gross Mass and Net Mass (KG)
- Item Price/Amount and Currency
- Valuation Method
- Nature of transaction
- Package Marks
- Number of packages
- Type of packages
- Invoice Number
- Document References and Codes
Mandatory under certain conditions
- National Additional Code
- TARIC Additional Code
- Country of Preferential Origin
- CUS Code
- Supplementary Units
- Statistical Value
- Tax Type
- Tax Base Quantity
- Tax Base Unit
- Payable Tax Amount /Currency
- Valuation Indicator
- Item Valuation (item additions and deductions)
- Item Addition/Deduction Code, Value & Addition/Deduction Currency

