P45: Leaving Employment
The crucial piece of paper you receive when quitting or getting fired.
What is a P45?
A P45 is a certificate given to you by your employer when you stop working for them. It shows how much tax you've paid on your salary so far in the tax year (6 April to 5 April).
The Four Parts
- Part 1: Your old employer sends this to HMRC.
- Part 1A: You keep this for your own records.
- Part 2 and 3: Give these to your new employer (or to Jobcentre Plus if you are not working).
Common Mistake: Losing It
By law, your employer must give you a P45. However, if you lose it, you cannot get a replacement. Employers do not issue duplicates.
If you start a new job without a P45, your new employer will have you fill out a "Starter Checklist" (formerly a P46). This helps them figure out your tax code, but it may result in you being placed on an emergency tax code temporarily, meaning you could overpay tax in your first few paychecks.
Worked Example: Switching Jobs Mid-Year
| Action | Consequence |
|---|---|
| Hand Part 2 & 3 to new HR | Tax code applied correctly. Paycheck is accurate. |
| Lose P45, use Starter Checklist | Emergency tax code. You overpay tax initially, then HMRC refunds it later in the year. |
Related Guides & Tools
Other Guides: P60 Guide, SA100
Tools: Income Tax Calculator