A cynic might say that you are required to contact HMRC when you are likely to owe them more money. Realistically, the opposite is also true: you should advise HMRC of any changes that could reduce your tax position.
The following notes are extracted from HMRC’s website and set out their requirements. You'll need to tell HMRC if you:
- get married or form a civil partnership
- start getting a second income
- become – or stop being – self-employed
- start or stop getting company benefits – like a company car or medical insurance
- start getting taxable benefits
You'll also have to let HMRC know if other income that you get – like savings or rental income – increases or reduces.
All these things and more can affect the amount of Income Tax that you have to pay.
Marriage or civil partnership where one partner was born before 6 April 1935
Tell HMRC if you get married or form a civil partnership and at least one partner was born before 6 April 1935 – you may be eligible for the Married Couple's Allowance if you pay tax.
If you get divorced or your civil partnership dissolves or you separate and you were getting the Married Couple's Allowance you will no longer be eligible so you need to let HMRC know.
Death of a spouse or civil partner
If your husband, wife or civil partner dies you need to contact HMRC if either of the following applies:
- you are claiming Married Couple's Allowance
- either of you claims Blind Person's Allowance and some or all of this was transferred to the other spouse or civil partner
Starting/stopping self-employment
You must tell HMRC that you're self-employed as soon as possible – even if you already fill in a tax return each year. If you don't tell them as soon as you begin self- employment you may have to pay an initial penalty.
Starting/stopping to receive company benefits
If you start to get taxable company benefits you should tell HMRC right away so that you don't get a large tax bill at the end of the year. Employers don't have to tell HMRC about any company benefits you get until the end of the tax year, unless it's a company car. HMRC will adjust your code number and start collecting all or some of the extra tax sooner. If you get a company car or change your company car, you only need to report the details to HMRC once you have the use of the car.
You should also tell HMRC if you stop getting taxable company benefits. They can change your tax code and make sure you don't pay too much tax.
Starting/stopping state benefits
If you start or stop getting state benefits it may affect your tax bill. The sooner you get in touch with HMRC, the sooner they can adjust your tax code to make sure you always pay what's due.
Reporting changes to your income
Changes in the level of certain types of income you receive needs to be communicated so that you don’t under or over pay tax.
And finally, if you change address
If you change address it's important to let HMRC know – even if you pay some or all of your tax through PAYE and have already told your employer or pension provider. Under the Data Protection Act they can't pass on your new address to HMRC.