Accountant & tax adviser in the UK for Irish businesses
From Ireland to Britain

Not always. An Irish company can trade with Great Britain through its Irish entity, but four UK questions still have to be answered: whether it has a UK establishment to register with Companies House (form OS IN01, within one month of opening for business), whether it must register for UK VAT, whether the Construction Industry Scheme applies to the work, and whether a permanent establishment arises under the UK–Ireland convention. A UK subsidiary becomes the better route once the UK activity is continuous or UK customers expect a UK entity.

Yes. We handle the incorporation, the Companies House identity verification (we are an Authorised Corporate Service Provider, ACSP AP019483) and the statutory registers, all remotely. There is no UK-residence requirement for directors or shareholders and you do not need to travel to the UK. Identity verification has been mandatory for every new director and person with significant control since 18 November 2025.

Under Article 5 of the 1976 UK–Ireland Double Taxation Convention, as amended, a building site or construction or installation project is a permanent establishment if it lasts for more than six months. That is a shorter threshold than many of the UK’s other treaties. Once a permanent establishment exists, the profits attributable to it are taxable in the UK and a UK corporation tax registration is needed. Shorter projects can still create UK VAT, CIS and payroll obligations.

Possibly from the first invoice. A business with no UK establishment is a non-established taxable person and HMRC applies no registration threshold to it: the UK £90,000 threshold is for UK-established businesses only. If your customer is UK VAT registered, the reverse charge may mean they account for the VAT instead, so the answer depends on who your customer is and on whether goods or services are supplied. Goods moving into Northern Ireland follow their own rules. We check all of this before your first invoice.

Yes. CIS depends on where the construction work is carried out, not where the contractor is based. A payment to an unregistered subcontractor suffers a 30% deduction, a registered subcontractor 20%, and a subcontractor with gross payment status 0%. Non-resident companies register with HMRC through the dedicated non-resident CIS registration, and we prepare the gross payment application where the tests are met.

Two separate questions. For income tax, Article 15 of the convention keeps an Irish employee’s pay taxable only in Ireland if they are present in the UK for no more than 183 days in the fiscal year concerned, their employer is not UK resident, and the cost is not borne by a UK permanent establishment; note that the 1976 convention counts days per fiscal year, not per rolling twelve months. For social security, the UK–Ireland social security convention lets a worker posted temporarily to the UK stay in the Irish scheme for a limited period with a certificate from the Irish authorities; we confirm the position for each posting and check whether a UK PAYE scheme is needed.

Yes. The UK–Ireland Double Taxation Convention was signed on 2 June 1976 and entered into force on 23 December 1976. It has been amended by protocols, most recently the 1998 protocol which took effect in the UK from 1 April 1999 for corporation tax and 6 April 1999 for income tax, and it is now read together with the Multilateral Instrument, whose synthesised text has had effect in the UK from 1 January 2020 for withholding taxes, 1 April 2020 for corporation tax and 6 April 2020 for income tax and capital gains tax. It governs business profits, permanent establishments, employment income, dividends, interest and royalties between the two countries.

The UK main rate is 25% on profits above £250,000 and the small profits rate is 19% on profits of £50,000 or less, with marginal relief in between; the 2026 Budget confirmed both rates for the year beginning 1 April 2028. The thresholds are divided between associated companies, so an Irish parent with several companies will usually see lower thresholds for its UK subsidiary.

No. The UK does not impose withholding tax on dividends under its own law, so the treaty ceilings in Article 11 (5% where the beneficial owner is a company controlling at least 10% of the voting power, otherwise 15%) are not needed for dividends paid out of the UK. Interest and royalties paid from the UK can be subject to UK withholding, and the convention and the MLI govern the rate; we handle the treaty clearance.

Irish citizens can live and work in the UK under the Common Travel Area, so for most people the question is tax, not immigration. Your UK tax residence is decided by the Statutory Residence Test, the year of arrival can be split into a non-resident and a resident part, and from 6 April 2025 new arrivals who were non-UK resident for the previous ten tax years can use the four-year foreign income and gains regime. Irish income you keep, such as rent, pensions or dividends, is dealt with under the convention. We prepare the UK side; your Irish adviser deals with Revenue.

Yes. We are appointed as your agent with HMRC and Companies House, receive the correspondence, file the returns and keep the statutory calendar, so your team in Ireland is never chasing a UK deadline. Ireland and the UK share a time zone, so same-day responses are the norm.

We hold ourselves to the strictest standards of confidentiality and data protection, in line with UK GDPR, with bank-level security on every system we use.