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If you think your tax code is wrong you need to tell HM Revenue & Customs (HMRC) as soon as possible to make sure you pay the right amount of tax. If it is wrong you may be due a tax refund, or need to pay more tax.
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HMRC issues your tax code based on information they have about your taxable income and allowances: it tells your employer or pension provider how much Income Tax to deduct from your wages or pension. Read the related guide below to help you understand your tax code.
When you start a new job you should give your new employer a form P45, if you have one from your last job. This shows:
If for some reason you don't have a P45, your new employer may give you a Starter Checklist to complete, or ask you relevant information before your first payday to tell HMRC about you. This will help your employer allocate a tax code and work the tax due on your first payday. HMRC will process the information you have provided on the Starter Checklist and where necessary, revise the tax code. It’s important that you complete the Starter Checklist or provide the relevant information your employer has asked as soon as possible before your first payday, so your employer knows what tax code to use. If you don’t you could end up paying the wrong amount of tax. You can also complete and print a copy of the Starter Checklist by following the link below. Give it to your employer; do not send the checklist to HMRC.
If you delay in providing your employer with the relevant information, your new employer will then use an 'emergency' or 'special basis' tax code. While you're on an emergency code you'll get the basic Personal Allowance - this may or may not be right for you. Your employer will send the information you’ve provided to HMRC so they can set up a record for you and review your tax code. Once HMRC has details of your previous income and tax paid for the tax year, they send your employer (and you) your full (correct) tax code. Your employer will deduct the correct tax in future and refund any overpaid tax.
You should wait at least 35 days before contacting HMRC where you have recently started a new job or pension as your new employer or pension provider will notify them automatically.
If your tax code is wrong you need to contact HMRC so they can correct it.
HMRC will need to know your tax reference and National Insurance number. Look for these numbers on official papers to do with tax, for example:
If you can't find any record of your tax reference and National Insurance number, HMRC will tell you what to do.
You can use the new HMRC email service to let them know that your tax code is wrong.