Most people on a payroll don't need to give too much thought to the tax that's automatically deducted from their pay.
Even if you file self-assessment, there's little to dwell on once your return is out of the way and you've paid the tax HMRC has calculated.
That said, mistakes can happen, and in some situations you may be in a position to claim back tax that's owed to you, rather than the other way around.
In recent news, taxpayers in Wales were accidentally charged at Scottish rates of income tax by HMRC, after some employers used the wrong tax code.
That mix-up saw anyone earning £43,431 to £50,000 in Wales taxed an extra 21% on that portion of income, while others paid one 1% more or less than they should have done.
The taxpayers affected have been told they don't need to do anything, as the mistake will be corrected through PAYE.
If you do find that you've paid too much tax, whether through your employer's payroll or self-assessment, you might need to take action yourself.
How to reclaim tax if...
You overpaid through PAYE
In many cases, HMRC will automatically send you a P800 tax calculation if you have paid too much tax on your pay or pension.
These are sent out after the end of the tax year in which you overpaid, and will include instructions on how to receive your refund.
It's important to scrutinise the calculation carefully and to inform them about any errors you notice, as failing to do so may result in a penalty.
If you want to make a claim sooner, or if you don't receive a P800, you can contact HMRC by phone, post, or your personal tax account.
You overpaid and are registered for self-assessment
You won't get a P800 if you're registered for self assessment, but you can make a request for a tax refund through your return instead.
You'll have the option to choose how the refund is paid to you, and HMRC will handle it after they have processed your return.
You made a mistake on your tax return
If you notice a mistake on your previous tax return that meant you overpaid tax, you can amend it online or by writing to HMRC.
This must be done within a year of the self-assessment submission deadline.
For changes to 2017/18 self-assessment returns, for example, you have until 31 January 2020 to make any amendments.
You were charged too much in payments on account
As payments on account are estimated based on the previous year's tax bill, you may need to claim a refund if your business goes through a drastic change during the year.
You can do this by using form SA303.
Time limits
You have four years from the end of the tax year in which you overpaid tax to make a claim. Outside of that timeframe, the year will be closed to most claims.
The following deadlines apply to the last four tax years:
| Year tax was overpaid | Deadline for claiming a refund |
| 2015/16 | 5 April 2020 |
| 2016/17 | 5 April 2021 |
| 2017/18 | 5 April 2022 |
| 2018/19 | 5 April 2023 |
Look out for scams
While genuine tax rebates and P800 forms are often sent at this time of year, fraudulent messages are also common in the spring and summer.
In March, April and May 2018, HMRC received 250,000 reports of tax scams and made more than 6,000 requests to have fake government websites shut down.
So, even if you're expecting correspondence about a tax refund, be wary of scammers posing as the tax authority and asking for your personal information.
HMRC will only inform you about tax refunds by post, through your employer, or through an email notification that tells you to log into your online account.
They will never send links or ask for your personal details in an email.
Contact us to discuss your finances.