Your tax code determines how much tax you pay from your wages. If it's wrong, you could be overpaying hundreds or even thousands of euros each year. Understanding your tax code—and spotting problems—is the first step to ensuring you're not paying more than you should.
Our specialists review tax codes every day and consistently find errors that cost people money. Here's how to check your tax code and what to look for.
📊 Tax Code Key Facts
- Where to find it: Your payslip or Tax Credit Certificate
- Common issues: Emergency tax, Week 1 basis, wrong credits
- Impact: Wrong code = wrong tax deducted
- Solution: Professional review finds and fixes issues
Understanding Your Payslip
Your payslip shows important tax information. Key things to look for:
Tax Credits
Most PAYE workers should have at least €4,000 in annual tax credits (€2,000 Personal + €2,000 Employee). If your payslip shows significantly less, or zero, something's wrong.
Tax Basis
Look for codes like:
- "Cumulative" – Normal, correct basis
- "Week 1" or "Month 1" – Non-cumulative basis, may cause overpayment
- "EMERG" – Emergency tax, definitely overpaying
Red Flags to Watch For
These signs suggest your tax code might be wrong:
- Low or zero tax credits: You should have at least €4,000 annually
- Emergency tax codes: "EMERG" on your payslip
- Week 1/Month 1 basis: Persisting for more than a few weeks
- Lower take-home than expected: Compared to your salary
- Lower than colleagues: On similar salaries
💡 Real Example
Kevin noticed his take-home pay seemed low compared to his colleagues. When we checked his tax, we found he'd been on Week 1 basis for 8 months after a job change—his cumulative credits hadn't been applied. His refund: €1,420.
What If Your Tax Code Is Wrong?
If you've been on the wrong tax code, you've likely overpaid tax. The good news: this money can be claimed back for up to four years. Our specialists will:
- Review your full history: Check all four claimable years
- Identify all overpayments: Emergency tax, Week 1, credit issues
- Find additional reliefs: Rent credit, medical expenses, work expenses
- Claim everything back: Submit your claim and handle all paperwork
Other Reliefs You Might Be Missing
Beyond tax code issues, there are many reliefs people don't claim:
- Rent tax credit – up to €1,000/year
- Medical expenses – 20% relief
- Work expenses – for many professions
- Working from home – for remote workers
The average refund our clients receive is €1,080. Learn more about how our process works.
Think Your Tax Code Is Wrong?
Our experts will review your tax and find any overpayments or missed reliefs.
Get Your Free Review →No refund, no fee • Average refund €1,080 • TAIN: 77632V
Frequently Asked Questions
Where can I see my Tax Credit Certificate?
Your Tax Credit Certificate is available through Revenue's myAccount. However, understanding what it means—and spotting problems—is where our specialists add value.
Will the wrong tax code fix itself?
Sometimes—but not always, and not automatically. If you've overpaid while on the wrong code, you need to claim that money back. Revenue doesn't proactively refund overpayments.
How far back can I claim overpaid tax?
Up to four years. If your tax code was wrong at any point since 2021, we can review and claim back the overpayment.