PAYE Modernisation replaced the old P30/P35 payroll system in Ireland on 1 January 2019. It was one of the most significant changes to employer payroll obligations in decades — requiring employers to report payroll information to Revenue in real time, on or before each pay date, rather than in a single annual return.
Seven years on, the system is embedded and Revenue is actively using the data it generates. What has changed since 2019 is not the system itself but Revenue’s appetite to cross-reference payroll data against other information — income tax returns, contractor payments, EIIS declarations — and to issue compliance interventions where inconsistencies appear.
This article — part of our payroll and employment guides — covers what PAYE Modernisation requires, where small employers commonly fall short, and what to do if your payroll arrangements are not fully up to date.
What PAYE Modernisation Actually Requires
Under the real-time reporting system, every time you pay an employee, you must submit a Payroll Submission Request (PSR) to Revenue via ROS (Revenue Online Service) on or before the pay date. The PSR contains, for each employee paid:
Their PPS number, name, and Revenue Payroll Notification (RPN) details. The gross pay for the period. PAYE, PRSI, and USC deducted. The period (weekly, fortnightly, monthly) and the pay date.
Revenue uses this data to update each employee’s tax record in real time. Employees can see their year-to-date income and deductions through myAccount on the Revenue website.
There is no longer a year-end P35 return. The annual reconciliation is replaced by the ongoing real-time PSR submissions throughout the year.
The Revenue Payroll Notification (RPN)
Before running payroll for any employee, you must retrieve their current RPN from Revenue. The RPN contains the employee’s current tax credits, tax rate bands, PRSI class, and USC rates — the information your payroll system needs to calculate deductions correctly.
If you process payroll without checking for updated RPNs, you may be using stale tax credit information. When Revenue issues a new or revised RPN — because the employee has changed their tax credits, started a second job, or had a life event that affects their tax position — your payroll system should pick this up automatically before the next pay run.
Failing to apply updated RPNs results in the wrong amount of tax being deducted from employees. If too little tax is deducted, the employee faces an underpayment that becomes their liability — but it can also attract Revenue’s attention to your payroll processes.
Where Small Employers Commonly Go Wrong
Not submitting on or before pay day. The most basic requirement — submitting the PSR before paying employees — is also the most commonly breached. Some employers submit after the fact, or submit weekly summaries for daily or ad hoc pay. Revenue has been increasingly issuing queries and penalty notices for late submissions.
Using emergency tax for employees without RPNs. When a new employee starts and you don’t yet have their RPN from Revenue, you are required to apply emergency tax rates. These are generally higher than the employee’s actual entitlement. Some employers are applying emergency tax indefinitely for employees who should have RPNs — this is incorrect, unfair to the employee, and creates an underpayment or overpayment situation that needs to be unwound.
Not reporting benefits in kind (BIK) through payroll. If you provide employees with benefits — a company car, health insurance, fuel, accommodation — these benefits have a taxable value that must be included in the payroll calculation and reported through the PSR. Many small employers pay for staff benefits without processing them through payroll, creating an unreported BIK liability.
Incorrect PRSI classification. Employees can be on different PRSI classes — Class A (most employees), Class S (self-employed, proprietary directors), Class J (employees over 66, certain part-time workers). Using the wrong class means the wrong PRSI rate is deducted and the wrong employer PRSI is paid. Revenue’s cross-referencing is increasingly identifying PRSI classification errors.
Processing payroll manually without a compliant system. Some very small employers still calculate payroll on a spreadsheet and submit to ROS manually. This is technically compliant if done correctly, but it is prone to error and does not automatically retrieve RPNs or apply updates. Most accountants would now recommend a basic payroll software solution — even for a business with one or two employees — to reduce the risk of errors and missed updates.
The Director’s Payroll — A Specific Minefield
For owner-managed companies where the director is also the primary employee, the payroll situation requires particular care.
A proprietary director — one who owns more than 15% of the company — is a Class S contributor for PRSI purposes. Class S PRSI is paid at 4% on income, with no employer PRSI element. This is different from Class A, which applies to most employees and involves both employee and employer PRSI contributions.
Revenue periodically reviews the PRSI classification of directors. Where a director who should be Class S has been classified as Class A (or vice versa), the resulting underpayment or overpayment of PRSI — plus interest and penalties — can be substantial.
The interaction between the director’s salary, dividends, and pension contributions also affects the payroll calculation. I cover the full picture in our guide to how directors can pay themselves tax-efficiently. These are connected decisions that should be made with tax planning advice, not simply by default.
What Auto-Enrolment Adds to the Payroll Obligation
Since September 2025, payroll submissions must also reflect auto-enrolment pension deductions for eligible employees. The PSR now includes employee and employer auto-enrolment contributions as part of the submission.
If your payroll software has not been updated to handle auto-enrolment, you are potentially submitting incomplete PSRs. Revenue will cross-reference payroll submissions against the NAERSA (auto-enrolment authority) records and identify employers who are enrolled to operate auto-enrolment but whose payroll submissions do not show the required contributions.
What to Do If Your Payroll Is Not Fully Compliant
If you have been running payroll without a compliant system, submitting late, or not processing all employees correctly, the starting point is an honest review of your current position.
In most cases, the most practical path to compliance is to engage an accountant or payroll bureau to review your current payroll records, identify any gaps or errors, and bring everything up to date. Revenue generally responds better to proactive disclosure and self-correction than to audit-triggered findings.
The cost of a payroll review is typically far less than the cost of a Revenue compliance intervention - particularly once interest and penalties on the underpaid amounts are calculated. If Revenue raises questions about your payroll reporting, having professional representation makes a significant difference. Read our guide on what happens during a Revenue audit.
For straightforward small businesses, outsourcing payroll to a reliable bureau is often the most cost-effective solution. The annual cost is modest, the risk of error is largely transferred, and the time saved is genuinely valuable.
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.