Brexit created a unique and genuinely complicated VAT situation for businesses trading between the Republic of Ireland and Northern Ireland. The Windsor Framework — the agreement that replaced the original Northern Ireland Protocol — has stabilised some aspects of the position, but Northern Ireland’s dual-system status means that businesses on both sides of the border regularly make VAT errors that cost them money and create compliance risk.
Understanding this properly requires understanding what the Windsor Framework actually does, not just what was said about it at the time it was agreed. This article is part of our library of cross-border business guides covering the practical implications for businesses in the Dundalk-Newry corridor.
Northern Ireland’s Unique VAT Status
Northern Ireland is part of the United Kingdom. For most tax purposes — income tax, corporation tax, National Insurance, stamp duty — it follows UK law. However, under the Windsor Framework (and the Northern Ireland Protocol before it), Northern Ireland follows EU VAT rules for goods transactions.
This means Northern Ireland simultaneously exists in two VAT systems:
For goods, Northern Ireland is treated as if it remains within the EU VAT area. VAT on goods sold from Northern Ireland to the Republic of Ireland (and vice versa) follows EU intra-community supply rules — not UK-to-third-country export rules. There is no customs duty on goods moving between the Republic and Northern Ireland.
For services, Northern Ireland follows UK VAT rules. The place of supply rules for services, the reverse charge mechanisms, and the VAT rates on services are determined by UK law, not EU law.
This split — EU rules for goods, UK rules for services — is the source of most cross-border VAT errors, as I outline in detail in my article on the VAT rules Irish and Northern Irish businesses keep getting wrong. Businesses naturally assume it is one system or the other. It is both, simultaneously, for different types of supplies.
Goods: The EU Intra-Community Rules Still Apply
When a Republic of Ireland business supplies goods to a business customer in Northern Ireland, the transaction follows EU intra-community supply rules — the same rules that apply to selling goods to a business in Germany or France.
The ROI supplier zero-rates the supply (0% VAT) and the Northern Ireland customer accounts for VAT on acquisition in their own VAT return. The Northern Ireland customer’s VAT number is required, and the transaction must be reported on the ROI supplier’s VIES (VAT Information Exchange System) return.
When a Northern Ireland business supplies goods to a business customer in the Republic of Ireland, the same principles apply in reverse. The NI supplier can zero-rate the supply; the ROI customer accounts for VAT on acquisition.
For business-to-consumer supplies of goods — selling to a private individual rather than a registered business — the rules are different and depend on whether distance selling thresholds are breached.
The practical implication: a Dundalk manufacturer supplying goods to a Newry business customer should be treating those sales as intra-community supplies (zero-rated), not as domestic Irish supplies (subject to the applicable Irish VAT rate). If the Dundalk supplier has been charging Irish VAT on goods sent to Northern Ireland, they have been overcharging — the customer has been paying VAT they should not have paid, and the ROI supplier has been collecting and remitting VAT incorrectly.
Services: UK VAT Rules Apply in Northern Ireland
For services supplied by a ROI business to a Northern Ireland business customer, the position is different from goods. Services to Northern Ireland follow UK place of supply rules rather than EU rules.
In most cases, the place of supply of B2B services is where the customer belongs — which for a NI customer means the UK. This means the reverse charge applies: the NI business customer accounts for UK VAT on the service received, and the ROI supplier does not charge Irish VAT.
This is the most commonly mishandled scenario. A Dundalk consultancy supplying professional services to a Newry business should not be charging Irish VAT. The supply is outside the scope of Irish VAT (place of supply is the UK), and the Northern Ireland customer accounts for UK VAT under the reverse charge.
If the Dundalk consultancy has been charging 23% Irish VAT on services to Newry clients, it has been overcharging — and the clients have been paying Irish VAT on a service where Irish VAT does not apply.
The GB Question: Great Britain Is Different From Northern Ireland
One further complexity that trips up Irish businesses is the distinction between Northern Ireland and Great Britain (England, Scotland, Wales).
The Windsor Framework applies specifically to Northern Ireland. Trade between the Republic of Ireland and Great Britain is third-country trade — there are customs formalities, rules of origin requirements, and the full UK-EU trade and cooperation agreement framework applies.
A ROI business exporting goods to a customer in Manchester faces a different VAT and customs position from a ROI business selling the same goods to a customer in Newry. Treating all UK addresses as the same is a common error that can result in customs duty exposure and VAT non-compliance.
For businesses that sell to customers across the UK — both Northern Ireland and Great Britain — the VAT and customs treatment needs to be assessed separately for each jurisdiction, not treated as a single “UK” category.
Common Errors and Their Consequences
Charging Irish VAT on goods supplied to NI business customers. Should be zero-rated intra-community supply. Consequence: overcharging the customer, incorrect VAT returns, potential adjustment and refund obligation.
Not applying the reverse charge on services to NI business customers. Instead charging Irish VAT. Consequence: the service is outside the scope of Irish VAT; Irish VAT should not have been charged. The customer has paid VAT they cannot reclaim (they need to reclaim UK VAT, not Irish VAT).
Treating all UK sales as the same. Not distinguishing Northern Ireland from Great Britain for VAT and customs purposes. Consequence: customs compliance failures on GB sales, potential import VAT issues, customs duty exposure.
Not registering for UK VAT where required. ROI businesses making taxable supplies of goods into GB above the UK registration threshold (£90,000 in 2026) must register for UK VAT. Northern Ireland is different — intra-community rules mean registration thresholds work differently. But for GB supplies, the UK threshold applies.
Incorrectly applying the reverse charge. The reverse charge on services from ROI to NI business customers requires the customer to be a UK VAT-registered business. If the NI customer is not VAT-registered, the reverse charge does not apply and different rules govern the supply.
Getting a Cross-Border VAT Review
If your business supplies goods or services to customers in Northern Ireland and you have not had your VAT treatment reviewed specifically in the context of the Windsor Framework and the post-Brexit rules, that review is overdue.
The errors described above are not hypothetical — they are happening regularly in businesses along the Dundalk–Newry corridor, as I discussed in my assessment of what Brexit has actually changed for Dundalk businesses. Some of them result in overcharging customers (an obligation to correct and potentially refund). Others result in under-declaring Irish VAT (a Revenue compliance exposure). Cross-border VAT arrangements are an area Revenue examines closely during compliance checks. If Revenue contacts you, read our guide on what happens during a Revenue audit. Both are more expensive to fix than preventing them in the first place.
A targeted cross-border VAT review typically takes a few hours of professional time and identifies the correct treatment for each category of supply you make. It is one of the most cost-effective compliance investments a cross-border business can make.
Paddy Malone FCA AITI
Paddy is the principal of Malone & Co. Chartered Accountants in Dundalk. A Fellow of Chartered Accountants Ireland and a Chartered Tax Consultant with the Irish Tax Institute, he has been advising businesses across County Louth and the North-East for over 35 years.