The Salary Calculator

I mentioned last month that The Salary Calculator has a sister site called Employed and Self Employed, which helps with tax and National Insurance calculations if you are both employed and self-employed at the same time (or in the same tax year).

The calculations can get quite complicated and how much you earn in employment affects how much tax and National Insurance you should pay on your self employment. In researching for this site, I discovered that it can be quite easy to pay too much National Insurance on your self employment income if you don’t know about the details of the regulations and if you assume that because you fill in your tax return with both incomes, it will be calculated correctly. This occurs because the National Insurance you pay on employment income (Class 1) is different from the National Insurance you pay on self-employment income (Class 4).

In both Classes of National Insurance, you pay nothing below a certain threshold, a higher “main” rate between that threshold and an upper threshold, and a lower “additional” rate above that threshold. If you are employed and self employed at the same time, you can end up paying a lot of the “main” rate on both of your incomes, whereas if you earned the same amount just from either employment or self employment, some of your income would be charged only the lower “additional” rate of National Insurance. Fortunately, HMRC know this and they will, if requested, take into account any National Insurance you paid through your employment when working out how much you owe them for self-employment. Unfortunately, they won’t do this by default – you need to ask for it.

This is done by applying for exemption of Class 4 National Insurance contributions. This doesn’t mean you pay no Class 4 (unfortunately!), it just means that they will take into account how much Class 1 you have paid when working out how much Class 4 to charge you. If you don’t apply for exemption, they will charge you the standard amount, which might be more than you owe. Luckily, you can apply for a refund if you have overpaid in previous tax years (although not normally until 1st February the year after you overpaid). As a rule of thumb, if each of your employed and self-employed incomes were more than the lower NI threshold (£7,605 for the 2012/13 tax year) and the total of the two incomes was close to or  more than the upper NI threshold (£42,475 for the 2012/13 tax year), you might be due a refund.

To make this easier, there is a new calculator on Employed and Self Employed which will help you work out if you might be due a National Insurance refund. Choose the tax year you’d like to check (as far back as 2005 / 6 – the thresholds were lower in previous years), enter your employment income and self-employment profit for that year, and the amount of Class 4 National Insurance you paid that year. The calculator will compare that with what it expects you to have owed for that year, and will let you know if a refund might be due. There are details on that page for how to contact HMRC and how to claim the refund. The calculator will do its best with the data you provide but it might not agree exactly with HMRC’s calculations – it can be used as an indicator and HMRC will be able to confirm whether or not a refund is due.

Good luck!