Reviewed by: MyTaxRebate Team on 10 Mar 2026 | Authority: s.865 TCA 1997
Quick Answer
Workers who change or leave a job in Ireland frequently overpay income tax and are entitled to a refund. Under s.865 TCA 1997, any income tax overpaid within the previous four years can be recovered. The most common causes are: emergency tax applied by the new employer before Revenue updated the tax certificate, unused credits for the period not worked, and a cumulative tax calculation not being performed at year end. In 2025, you can claim for overpayments from 2022, 2023, 2024, and 2025. MyTaxRebate reviews your full employment history across all four years and submits a comprehensive claim to Revenue on your behalf.
What This Page Covers
- ✓Why changing or leaving a job often leads to a tax overpayment
- ✓What happens to your tax credits when PAYE stops mid-year
- ✓How emergency tax works and why it causes overpayments
- ✓How to claim the overpayment from a previous employer under s.865 TCA 1997
- ✓What documentation is required for a job-change tax refund
Key Facts at a Glance
- ✓Legal basis: s.865 TCA 1997 - four-year right to recover overpaid PAYE tax
- ✓Most common cause: emergency week-one tax applied by the new employer for weeks or months
- ✓Unused credits: annual credits allocated for a full year but only used for the months worked
- ✓Available years in 2025: 2022, 2023, 2024, and 2025
- ✓Documentation needed: P45 from previous employer, payslips from both employers
- ✓Revenue processes valid agent claims within 5 - 15 working days
- ✓Backdate up to four years - in 2025, claim for 2022, 2023, 2024, and 2025
Why Job Changes Cause Tax Overpayments
When you leave one employer and start with another, the PAYE system does not automatically transfer your accumulated tax credit usage from the old job to the new one. Your new employer starts the PAYE calculation either from the information on your P45 (if you provided it promptly) or, more commonly, on a week-one or month-one emergency basis until Revenue updates your tax credit certificate for the new employment. During emergency basis, your employer deducts tax without taking account of credits already used or credits available for the year - this almost always results in excess deductions.
The legal right to recover these overpayments is established under s.865 TCA 1997. Revenue must issue a refund of any tax collected in excess of your actual liability when a valid claim is made within four years. In 2025, this covers overpayments from 2022, 2023, 2024, and 2025.
Unused Credits When Employment Ends Mid-Year
Your annual tax credits (€1,875 Personal Credit + €1,875 Employee Credit = €3,750 in 2025) are allocated for a full year of employment. If your employment ends in, say, June, your employer will have been deducting PAYE based on the cumulative method up to that point. However, the credits for July to December have not been used against any income - you are entitled to a refund of the tax that would have been offset by those unused credits if you had continued working.
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How Revenue Holds Your Prior Employment Records
Every employer in Ireland is required to submit real-time PAYE reporting data to Revenue for every payroll run. This means Revenue holds a complete record of your income and PAYE deductions from every employer for every pay period. When you claim tax back for a year when you had a previous employer, Revenue can access those historical payroll records directly. You do not necessarily need your old payslips or P45 to claim - Revenue already holds the data. MyTaxRebate accesses this information through the Revenue agent portal and uses it to calculate the correct refund for each available year.
Emergency Tax and Previous Employment
When you start a new job, your new employer may place you on emergency tax until Revenue issues a Tax Credit Certificate for that employment. During the emergency period, your standard annual credits are not applied, and you may be taxed at a higher rate. This is one of the most consistent sources of overcollection when changing employer. Under s.865 TCA 1997, the year-end position is recalculated applying the correct credits across the full year, correcting the overcollection from the emergency period. Workers who changed employer in any of the four available years (2022, 2023, 2024, or 2025) should review those years specifically.
Claiming for Years When You Had Multiple Jobs
A year in which you had two employers (consecutively or simultaneously) requires a year-end review to ensure the correct tax position is established. Where credits were split or allocated to only one employer, the other employment may have deducted PAYE without credit offset, resulting in overcollection. The year-end calculation applies all credits across the combined income from both employers and determines the correct total liability, generating a refund where PAYE overcollected across the combined employments.
One of the most common situations where a tax refund arises from a previous employer relationship is emergency tax. When you start a new job and your new employer does not yet have your tax credit certificate from Revenue, they may apply emergency tax - deducting at a flat rate without any credits. Once Revenue issues the correct certificate, your employer adjusts future payslips, but if you left that employer before the adjustment was fully applied, the emergency tax period may have resulted in an overpayment that is never corrected through the payroll.
In this situation, you are entitled to recover the overpayment through Revenue's your Revenue record by reviewing the end-of-year statement for the year in question and confirming that the correct credits were applied. Under section 865 TCA 1997, this can be done for any of the four prior tax years. Revenue holds all payroll data submitted under PAYE Modernisation, so even if the employer is no longer operating, Revenue still has the information needed to calculate your refund accurately. The claim is submitted entirely through your Revenue record without any involvement from the former employer.
One of the most common situations where a tax refund arises from a previous employer relationship is emergency tax. When you start a new job and your new employer does not yet have your tax credit certificate from Revenue, they may apply emergency tax - deducting at a flat rate without any credits. Once Revenue issues the correct certificate, your employer adjusts future payslips, but if you left that employer before the adjustment was fully applied, the emergency tax period may have resulted in an overpayment that is never corrected through the payroll.
In this situation, you are entitled to recover the overpayment through Revenue's your Revenue record by reviewing the end-of-year statement for the year in question and confirming that the correct credits were applied. Under section 865 TCA 1997, this can be done for any of the four prior tax years. Revenue holds all payroll data submitted under PAYE Modernisation, so even if the employer is no longer operating, Revenue still has the information needed to calculate your refund accurately. The claim is submitted entirely through your Revenue record without any involvement from the former employer.
Check Your Claim
MyTaxRebate can review your position and guide the next step.
Tax Scenarios
Scenario 1: New Job, Emergency Tax Applied
A warehouse supervisor left his job in March 2023 and started a new role in April. His new employer placed him on week-one emergency tax for six weeks until Revenue updated his certificate. He overpaid approximately €920 during that period. He also had €480 in qualifying medical expenses. MyTaxRebate submitted a four-year review and recovered €1,380 in total - the emergency tax overpayment, medical relief, and unused credits from the month between jobs.
Scenario 2: Unused Credits After Leaving Mid-Year
A marketing manager left her job in July 2022 to take a career break. Her employer deducted PAYE correctly up to July. The remaining five months of credits for 2022 were unused. MyTaxRebate calculated the refundable credit balance, combined it with €1,100 in medical expenses and her flat-rate marketing expense allowance, and submitted for 2022 and 2023. Total refund: €2,040.
Scenario 3: Two Employers in Same Year
A retail worker had two jobs in 2024 - one from January to June and a second from August to December. Revenue did not issue an updated certificate to the second employer until September, meaning the second employer deducted tax without credits for August. The gap month (July) also had unused credits. MyTaxRebate identified the double-counting and overpayment, submitted for all four years, and recovered €1,650.
Common Mistakes To Avoid
- ✗Not providing the P45 to the new employer promptly: Delays in transferring the P45 extend the period of emergency tax deduction. Provide the P45 to your new employer on or before your first pay date to prevent unnecessary overpayment.
- ✗Assuming the previous employer handles the refund: Previous employers do not process tax refunds. Refunds are always paid by Revenue directly to you, not by the employer who deducted the tax.
- ✗Not claiming for all jobs in the same year: If you had multiple employments in any year, each one is relevant to the year-end calculation. MyTaxRebate reviews all employers across all four years to ensure the full picture is captured.
- ✗Missing the four-year deadline for earlier job changes: If you changed jobs in 2021 or earlier and have not claimed, those years are now time-barred. For job changes from 2022 onwards, act promptly to avoid the same outcome.
- ✗Only claiming for the job-change year and not subsequent years: A job change may create an overpayment in the change year but the same worker may also have ongoing unclaimed reliefs in subsequent years. Always review all four available years together.
When This Does Not Apply
Key Takeaways
- ➤ Submit your P45 to new employers promptly to minimise emergency tax periods
- ➤ Review all four available years (2022 - 2025) whenever a job change occurred in any of them
- ➤ Check for qualifying medical and employment expense reliefs in addition to the credit refund
- ➤ Act before 31 December 2026 if any job change occurred in 2022
- ➤ Use MyTaxRebate to submit - we handle the full employment history review and Revenue submission
Check Your Claim
MyTaxRebate can review your position and guide the next step.
Frequently Asked Questions
Can I claim tax back after changing jobs in Ireland?
Yes. Job changes are one of the most common causes of PAYE overpayments in Ireland. Under s.865 TCA 1997, you are entitled to recover any income tax overpaid within four years. Overpayments from job changes typically arise from emergency tax applied by the new employer, unused credits for the period between jobs, and year-end balancing where credits were not fully absorbed. MyTaxRebate reviews your full employment history and submits a comprehensive claim to Revenue on your behalf.
How do I get tax back when I leave a job in Ireland?
When you leave a job in Ireland, ensure your employer issues a P45 and that all pay and tax deducted to date is correctly recorded. At year end, if more tax was deducted than your annual liability requires (which is common when employment ends mid-year), you are entitled to a refund under s.865 TCA 1997. MyTaxRebate handles the claim by reviewing your P45, payslips, and any qualifying expenses, and submitting directly to Revenue. Revenue typically processes valid claims within 5 - 15 working days.
What is emergency tax and how does it affect my refund?
Emergency tax (also called week-one or month-one basis) is applied by an employer when they have not received a current tax credit certificate from Revenue for a new employee. Under emergency basis, the employer deducts tax without taking account of your annual credits or previous income for the year, which almost always results in excess deductions. Once Revenue issues the correct certificate and cumulative basis is restored, any overpayment from the emergency period is included in your year-end refund. MyTaxRebate identifies and recovers these overpayments as part of every job-change review.
How far back can I claim tax back from a previous job?
Under s.865 TCA 1997, you can claim tax back from a previous employer for up to four years from the end of the relevant tax year. In 2025, this means job changes and overpayments from 2022, 2023, 2024, and 2025 are all claimable. The 2022 deadline closes on 31 December 2026. If you changed jobs in 2022 and have not yet claimed, act promptly to ensure this year is included in your review.
Do I need my P45 to claim tax back from a previous employer?
A P45 is helpful and confirms the pay and tax deducted by your previous employer to the date of leaving. However, if you do not have a P45, MyTaxRebate can access your employment and payroll information through Revenue's records as your appointed tax agent. Revenue holds employer payroll submissions for all years within the four-year window, so missing P45 documents do not prevent a valid claim from being submitted and processed.
