By Bébhinn Egan, 10th June 2026
If your business is involved in construction, forestry or meat processing in Ireland, Relevant Contracts Tax (RCT) is something you can’t afford to overlook. RCT is a withholding tax that applies when a principal contractor makes payments to a subcontractor under a relevant contract, and all compliance is managed online through Revenue Online Service (ROS).
For many businesses, the challenge is not just understanding the tax rates, it’s knowing whether a contract falls within scope, who has the filing obligations, and what happens if work is being carried out in Ireland by a non-resident entity.
In this guide, we break down RCT in plain English: what it is, which activities are covered, the three RCT rates, what principal contractors must do, what subcontractors need to know, and why non-resident contractors working in Ireland should pay close attention.
What is Relevant Contracts Tax (RCT)?
RCT is a tax deduction-at-source system that applies to certain payments made by a principal contractor to a subcontractor in the construction, forestry and meat-processing industries. The purpose of the system is to ensure that tax is collected from relevant payments as they are made. All RCT compliance, filing and payment activity is carried out through ROS.
Revenue’s guidance makes an important distinction: RCT applies where relevant operations are carried out under a relevant contract and the person paying the subcontractor is a principal contractor who is obliged to operate RCT. That means not every contract involving construction-type work automatically triggers RCT. For example, if a private householder hires a builder directly, RCT generally does not apply, but if that builder then engages subcontractors, the builder may have to operate RCT on those payments.
Which Activities are Covered by RCT?
Revenue lists a wide range of activities that come within the scope of RCT. In construction, that includes not just obvious building works such as constructing, altering, repairing, extending or demolishing buildings and structures, but also many related activities such as installing heating, lighting, ventilation, drainage, sanitation, water supply and telecommunications systems. It also includes activities integral to construction projects, such as site clearance, excavation, tunnelling, laying foundations, scaffolding, landscaping connected to a build, and haulage for hire of materials or machinery used in those works.
RCT also applies to certain forestry operations, including thinning, felling, planting, maintaining forests and transporting materials or machinery for use in those activities. In the meat-processing sector, it can apply to slaughtering, packaging, preserving, hauling carcasses and cleaning premises where those activities are carried out.
Because the scope is broad, it is often sensible to send Revenue’s list of relevant operations to a client and ask them to confirm whether their trade or contract matches any of the listed activities. This is especially useful where the contract sits in a grey area: for example, where supply and installation are bundled together, or where a service involves both labour and materials. Revenue’s manuals also note that mixed contracts may need to be apportioned so that RCT is applied to the part of the consideration that relates to construction operations.
Who is a Principal Contractor?
A business is generally a principal contractor if it uses a subcontractor to carry out relevant operations on its behalf in construction, forestry or meat processing. Revenue also treats a wider group as principals, including certain connected companies, local authorities, housing associations, Government Ministers, public bodies, and businesses involved in gas, water, electricity, hydraulic power, docks, canals, railways and telecommunications system installation, alteration or repair.
Revenue also makes clear that a person or company can be a principal contractor even if they are not what most people would think of as a mainstream construction business. That is one reason RCT can catch businesses by surprise, especially where work is subcontracted out as part of a broader commercial project.
The Three RCT Rates
Revenue operates three RCT deduction rates for subcontractors: 0%, 20% and 35%. The applicable rate depends on the subcontractor’s compliance record. A subcontractor with an up-to-date tax compliance record may qualify for 0%; a subcontractor with a substantially up-to-date compliance record is generally at 20%; and a subcontractor with a poor compliance record, or who is not registered with Revenue, may be subject to 35%.
Revenue’s Tax and Duty Manual explains that new tax registrations are automatically granted a 20% rate because a three-year compliance history does not yet exist. It also explains that the 0% rate is linked to satisfying a number of criteria, including record-keeping, fixed place of business and compliance over the previous three years, although Revenue can disregard some requirements in certain circumstances where the person satisfies them that this is appropriate.
So, in practical terms:
- 0% may apply where the subcontractor has a strong compliance history and meets Revenue’s conditions.
- 20% is the standard rate for subcontractors who are registered and broadly compliant, including many new registrations.
- 35% can apply where the subcontractor is unregistered, has compliance issues, or cannot be properly verified by Revenue.
What Does the Subcontractor Need to Do?
A subcontractor must provide the principal contractor with the information needed to notify the contract to Revenue, including the subcontractor’s official name as recorded by Revenue and their Tax Reference Number (TRN). They should also provide proof of identity, such as a passport, driving licence or tax registration details. Once the principal contractor notifies Revenue of the contract, Revenue issues the subcontractor with a contract confirmation letter, which also confirms the RCT deduction rate.
If the principal contractor deducts RCT, Revenue automatically credits that amount to the subcontractor’s tax record. Once a relevant tax return is filed and the tax liability falls due, Revenue can automatically offset those RCT credits against liabilities such as PAYE, Income Tax, Corporation Tax or VAT.
This is an important practical point: RCT is not simply “lost money” to the subcontractor. It is a tax credit that may reduce other tax liabilities or become refundable, depending on the subcontractor’s circumstances and filings.
What Does the Principal Contractor Need to Do?
The principal contractor carries the main compliance burden under RCT. Revenue requires the principal to: register as a principal contractor, notify Revenue of relevant contracts, notify Revenue before making payments, provide deduction details to the subcontractor where tax is withheld, check the deduction summary/return, and pay over the RCT deducted.
1) Register as a principal contractor
A person who becomes a principal must register with Revenue, and Revenue’s manual states this should be done within 21 days of entering into the first relevant contract as a principal. Registration can be completed through Revenue’s eRegistration facility.
2) Submit a contract notification
The principal must notify Revenue as soon as a relevant contract is entered into. Revenue expects details including the subcontractor’s tax reference number, name, sector, nature of work, location, dates, estimated value, and confirmation that the contract is not one of employment. When the contract is notified, Revenue creates or associates a Site Identifier Number (SIN) for the site or project.
If there are several sites, it is vital to ensure the correct subcontractors are linked to the correct site and contract. This is one of the areas where administrative errors can create avoidable compliance issues.
3) Submit a payment notification before paying
Before making each payment to a subcontractor, the principal must submit a payment notification to Revenue showing the gross amount of the payment and the payment date. Revenue then issues a deduction authorisation, which confirms the RCT rate and the amount that must be withheld, if any. Only then should the principal pay the subcontractor the net amount.
If a payment notification is submitted incorrectly, it cannot simply be edited: the principal should cancel it and file a new notification with the correct details.
4) Check the deduction summary/return
At the end of the return period, Revenue prepares a deduction summary based on the payment notifications submitted. This acts as the principal’s return unless amended. Revenue says the summary should be checked and, if necessary, amended before the 23rd of the following month.
5) Pay over the RCT deducted
Revenue’s guidance states that RCT deducted should be paid by the 23rd of the month following the end of the return period if paying electronically, or the 14th if paying by other means.
What Happens if the Principal Gets it Wrong?
Revenue can impose penalties where a principal contractor makes an unreported payment — meaning a payment is made other than in accordance with a deduction authorisation. The penalty depends on the subcontractor’s status at the time of payment: 3% where the subcontractor is at 0%, 10% where they are at 20%, 20% where they are at 35%, and 35% where the subcontractor is unknown.
That means a principal contractor who pays too early, skips the payment notification step, or pays outside the deduction authorisation process can face a significant cost, even before dealing with the underlying tax issue itself.
Does RCT Apply to Non-Resident Entities?
Yes. Revenue is explicit that RCT applies to non-resident subcontractors where the work is carried out in Ireland. If relevant operations are being carried out in Ireland, the principal contractor should deduct RCT from the gross payment — even where the subcontractor is non-resident. Revenue also states that a non-resident principal contractor can be obliged to register and operate RCT if it engages a contractor to carry out relevant operations in the State.
This is a key point for overseas businesses entering the Irish market: even if a company is not Irish-resident, RCT may still apply if the contract work is being carried out in Ireland.
Revenue further explains that non-resident subcontractors who are registered for RCT may apply for a refund during the year, and that in the construction sector the VAT reverse charge generally applies, meaning the principal contractor accounts for VAT directly to Revenue instead of the subcontractor charging Irish VAT on the service.
Common RCT Mistakes Businesses Make
The most common RCT problems are often administrative rather than technical. Businesses may assume a contract is outside scope when it actually contains construction operations, fail to register as a principal on time, forget to make a payment notification before paying, or assume a non-resident entity is outside the Irish rules when it is not. Revenue’s guidance makes it clear that these areas all matter.
Another common issue is treating the subcontractor’s indicative rate on the contract acknowledgement as if it were the final rate for payment purposes. Revenue’s manual says the actual tax to be withheld is confirmed through the deduction authorisation issued after the payment notification, not by relying on earlier assumptions.
Need Help Registering for RCT?
If you are unsure whether your business falls within the scope of RCT, or whether you need to register as a principal contractor, subcontractor, or both, it is worth getting advice before payments begin. Early registration and correct setup can help avoid unnecessary 35% deductions, filing errors and penalties.
At Company Bureau, we can assist with RCT registration for principal contractor and subcontractor status. Our fee is €75 + VAT per contractor status required. So, if a business needs to register as both a principal and a subcontractor, the total fee would be €150 + VAT.
If you would like help with RCT registration or want us to review whether your activities are likely to fall within Revenue’s list of relevant operations, please get in touch with our team.
Disclaimer: This article is for guidance purposes only. It does not constitute legal or professional advice. No liability is accepted by Company Bureau for any action taken or not taken in reliance on the information set out in this article. Professional or legal advice should be obtained before taking or refraining from any action as a result of this article. Any and all information is subject to change.
