How to Check Your Income Tax and Tax Code

Knowing exactly how much Income Tax you've paid, and whether your tax code is correct, helps you avoid nasty surprises and spot refunds you might be owed. This guide walks through checking last year's tax, this year's tax, and your tax code, using HMRC's official online services.

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Quick Overview

What You Want to Check	Time Period Covered	Where to Check
Income Tax paid last year	6 April 2025 – 5 April 2026	Personal tax account or HMRC app
Income Tax for this year	6 April 2026 – 5 April 2027	Personal tax account or HMRC app
Your current tax code	Current tax year	Personal tax account (current Income Tax section)
Estimated take-home pay	Current tax year	HMRC's Income Tax estimator

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How to Check Your Income Tax From Last Year

If you want to know what you paid in the previous tax year, HMRC provides an online service that shows the final figure once your tax has been calculated.

What the Service Covers

The check-your-Income-Tax service shows what you paid for the tax year running from 6 April 2025 to 5 April 2026. HMRC works out each person's Income Tax for the previous year between June and November, so figures aren't available immediately after the tax year ends.

Who Can't Use It

This service only works if HMRC calculated your tax outside of Self Assessment. If any portion of last year's Income Tax was paid through a Self Assessment return, this online checker won't show your figures — you'll need to look at your Self Assessment account instead.

Getting a Refund or Paying What You Owe

Some people can also use this same service to claim a refund or settle a tax bill. This only applies if you've received a P800 tax calculation letter from HMRC confirming you're eligible to act online.

Steps to Check Last Year's Tax

1. Go to the official HMRC "Check your Income Tax" service.
2. Sign in with your Government Gateway details, or create an account if you don't have one.
3. Verify your identity if prompted — usually with a passport or driving licence.
4. Select the previous tax year to view your calculation.
5. Alternatively, open the HMRC app and check the same information from your phone.

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How to Check Your Income Tax for the Current Year

For up-to-date figures, HMRC offers a separate service covering the tax year in progress — currently 6 April 2026 to 5 April 2027.

What You Can Do With This Service

Once signed in, you can:

• Check your tax code and Personal Allowance
• View your estimated income from jobs and pensions, and what tax you're likely to pay
• Update your income details if your job or pension has changed
• See whether your tax code has recently changed, and why
• Tell HMRC about anything that might affect your tax code
• Update your employer or pension provider information

Keeping this information current matters — outdated employer or income details can mean you end up paying too much or too little tax throughout the year.

Who Can't Use This Service

If Self Assessment is your only method of paying Income Tax, this current-year checker isn't available to you. Self Assessment taxpayers should use the Self Assessment tax calculator instead to estimate their bill.

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How to Check Your Tax Code

Your tax code determines how much tax-free income (your Personal Allowance) you get before tax is deducted from your pay. Checking it regularly helps you catch errors early.

Where to Find It

Your tax code sits inside the same current-year Income Tax service described above. After signing in:

1. Open your personal tax account or the HMRC app.
2. Select the current Income Tax section.
3. Your tax code will be listed next to your estimated income and Personal Allowance.

You'll also find your tax code on a payslip, a P45, or a P60 if you'd rather check it that way.

Why Your Tax Code Might Change

HMRC updates tax codes when your circumstances change — for example, starting a new job, receiving a workplace benefit, gaining or losing a pension, or having outstanding tax from a previous year collected through your pay. If your code changes, the online service explains the reason.

What to Do If It's Wrong

If your estimated income or employer details are out of date, update them directly in your personal tax account. This is the fastest way to correct your tax code without waiting for HMRC to catch the discrepancy through a future review.

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Estimating Your Income Tax and National Insurance

If you'd rather plan ahead than check historical figures, HMRC also provides an estimator tool for the current tax year.

Who It's For

This tool suits employees who have tax and National Insurance deducted monthly by their employer. It calculates your likely take-home pay after:

• Income Tax
• Any pension contributions
• Any student loan repayments

Who Should Use a Different Tool

If you're registered for Self Assessment, use the Self Assessment tax calculator instead, since your circumstances usually involve income the standard estimator doesn't account for.

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Signing In: What You Need to Know

All of these services run through the same Government Gateway sign-in system.

• New users: you can create sign-in details the first time you visit.
• Identity verification: HMRC may ask you to prove who you are the first time you sign in. This typically involves photo ID, such as a passport or driving licence.
• Welsh language option: each service is also available in Welsh (Cymraeg), with a dedicated link on the English version of the page.
• Mobile access: the HMRC app mirrors most of these services, so you can check your tax code or last year's tax bill without opening a browser.

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Claiming a Refund

If you discover you've overpaid tax, don't assume it will sort itself out automatically. You can usually claim a refund if:

• HMRC has sent you a P800 letter confirming you're due money back, or
• You spot an overpayment yourself while checking your current or previous year's tax

Refund claims are made through the same personal tax account, or via the dedicated tax refund claim service linked from your P800.

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Summary

Checking your Income Tax and tax code takes a few minutes once you're signed in to your personal tax account or the HMRC app. Reviewing last year's figures confirms what you actually paid, checking the current year keeps your tax code accurate, and the estimator helps you plan your take-home pay. Self Assessment taxpayers should rely on their Self Assessment records and calculator instead of these standard checkers.