Triginta provides a unique calculator for self-employed people to calculate how much to set aside for tax and national insurance through the year.

One of the problems that self-employed people face is knowing how much they should set aside from their earnings for tax and national insurance. For someone in employment, this is done for them by their employer, using the PAYE scheme.

But a self-employed person has to work this out for themselves, and it is often a source of worry, because they could end up not setting enough aside or, just as bad, setting aside too much.

There are numerous calculators available on the internet to help self-employed people work this out. But typically, these just ask the self-employed person to estimate how much they’re going to earn over the year, and work out how much tax they’d be liable for by averaging it evenly over twelve months.

A good example is HMRC’s own ready reckoner, which is shown in the image below, taken from the HMRC website.

There are versions of similar calculators on other websites, including paid book-keeping packages charging more than Triginta.

This is only really helpful if you can estimate your profits accurately and you’re only likely to be able to do this as you get close to the year-end. But for most self-employed people, both their earnings and their business expenses vary from one month to another, so a simple average for the year isn’t helpful.

What a self-employed person really needs is something close to PAYE, a system that calculates the tax and national insurance in detail every month and then tells them how much they have left as net earnings, a bit like the take home pay figure that they’d get under the PAYE scheme.

Triginta does exactly that. In effect it does a mini tax calculation every month, so the self-employed user knows exactly where they stand. It is updated as the year progresses and ensures that, when you come to the end of the year, you’ll have the right amount set aside.

The Triginta calculator can be used if you combine being self-employed with paid employment, and it will  

also take account of tax reliefs for pension contributions. All you have to do is make any adjustments for things like interest from savings or share dividends, and relief for charitable donations, which you will need to do at the end of the year when you complete your tax return.