What Is a P45 Form?

Learn everything you need about the P45 form and its importance.

Updated: May 18, 2024
Matt Crabtree

Written By

Matt Crabtree

Jason Mountford

Edited By

Jason Mountford

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If you've worked in the UK, you've probably been given a P45 from a previous employer or at least have heard of a P45 form. They're an essential document that helps you enter new employment with the correct information for tax payments for the tax year.

The P45 form is an important document that most people are aware of.

However, fewer understand what a P45 form includes and its importance. In this article, you'll learn about the P45, why you need it and how you get a P45 from your former employer ready for your new employer.

What Is a P45 Form?

A P45 form is an important document that contains your correct tax code and is the best way to pass tax and payroll information from old employer to new employer. A copy of your P45 form is handy for keeping your tax records. A P45 is valid only for the same tax year it is given.

A P45 form contains the following information:

  • Employee identification: A P45 form includes details about you to verify you are who you are. Your P45 will also have your national insurance number on it.
  • Tax code: Your tax code will be on the form and ensures you're not paying too little or too much tax when you join new employment.
  • Taxable pay: A P45 form shows any taxable income previously received this tax year (6 April to 5 April) and any tax paid, and it will show your previous national insurance contributions.
  • Former employer's PAYE: The p45 form shows your old employer's pay as you earn tax references.

The P45 form covers anything to do with tax, so if you need your tax code or are curious about how much you've paid in the tax year from a specific employer, your P45 will tell you everything you need to know.

The P45 document is vital for beginning your new employment because it lets your new employer know which tax code must be applied to your salary. Your tax code determines the tax and national insurance deductions from your pay.

If you’re charged too much tax because the new payroll system doesn't have the right tax code, you could later claim tax refunds, but it would be easier for your new employer to have your correct tax code from the start of your employment. Usually, if you're charged too much tax, you'll automatically receive a tax refund after the tax year ends.

If you don’t have access to your tax code, you'll get a temporary emergency tax code that will later be replaced when you or your employer submits the correct code to HM Revenue and Customs (HMRC).

An emergency tax code is provided when HMRC doesn't have sufficient information on your income and tax liabilities. Once HMRC has your correct information, they can update your tax payments and other deductions accordingly.

How Can You Get a P45 Form

You should be issued a P45 as soon as you leave employment.

The employer issues the P45, P60 (for income tax), and other documentation as a legal requirement. It's not a complicated process, as it's generated automatically through the company payroll system when an employee leaves.

Your previous employer will send you your P45 in the post or digitally.  You can see the information provided from your P45  by signing into your personal tax account on the Government Gateway. However, this isn’t a copy of your P45, and it can’t be used as such. 

If you've already left your previous job and have yet to receive your P45, you may need to contact them to forward you a copy, or you can contact HMRC and inform them of the situation, and they can handle it. If an employer fails to send out a P45 after contact with HMRC, they could be fined.

There is no legal time limit for when you should receive your P45, but ideally, it should be ready for the new job. Employers are generally expected to provide the necessary documentation for the employee's final day.

What Happens if You Lose Your P45?

If you lose your P45 form, you cannot get a replacement, unless your ex-employer is prepared to re-issue it to you.

Instead, your new employer will either ask you for the relevant details about your finances and forward them to HMRC or, more likely, give you a starter checklist form to fill out. You may also have to fill out a starter checklist if the tax year changes between leaving a job and starting a new one.

A starter checklist informs HMRC of a new employee added to the PAYE system and provides them with their personal financial information regarding tax. The form ensures the right amount of tax deductions from your salary and makes sure you’re eligible for social welfare benefits like Statutory Sick Pay.

Filling out a starter checklist form is straightforward; you must answer the questions correctly and check for any mistakes before submitting it. The starter checklist includes questions include:

  • Personal details: You'll be asked for basic information like your name, date of birth, and address.
  • National Insurance number: You'll need to provide your National Insurance (NI) number to ensure your National Insurance contributions and tax are recorded against your name. Every person in the UK is given a NI number when they turn 16.
  • Tax code: Your tax code determines how much tax you'll pay each tax year. If your tax code is wrong, you could pay too much or too little tax.
  • Start date: You must include the relevant dates when you leave and start a new job.
  • Student loan: If you have a student loan, you'll need to provide relevant information about your loan so the right payments are deducted from your salary.
  • Employee statement: This section of the form is where you'll mention any other jobs you may have. There will be three options; you’ll need to tick one of them most relevant to you. Statement A is for employees with no other source of income besides wages from the current role. Statement B is for those with other sources of income, like a pension and salaries from their current job. Statement C is for employees with more than one job or changing positions during the current tax year.

Once you've filled in the starter checklist, hand it back to your employer so they can submit it to HMRC. Once all your correct information is in your new employer's PAYE system, you can start paying the right amount of tax, and you can get paid each month knowing you're paying what you need to.

Sometimes things get lost, but try to keep your P45 and other important documentation regarding tax safe. HMRC can conduct tax investigations up to 20 years after a given tax period, so keeping your records safe will help you out if an investigation is to happen.

Final Thoughts

A P45 is important as it provides your new job with all your tax information from your previous employment so they know how much you've already paid in the current tax year and adjust your new pay in their payment software accordingly.

P45 forms are a legal requirement from your ex-employer. However, if you lose it before starting your new job, it's not the end of the world. You can fill out a starter checklist form and ensure you're not paying more tax than needed.

Related Guides:


Do I Need a P45 to Start a New Job?

Can I Get a P45 Online?

What Do I Do if My Employer Fails to Give Me a P45?

How Long Is a P45 Valid?

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