Tax returns can be extremely daunting for someone who has recently gone self-employed. If you had previously been in an employed role, you would not have had to worry about working out how much tax you need to pay, it would have been taken out of your wage at source. However once you enter the world of self-employment, you need to do something called a self-assessment. This is where you declare all your earnings and expensive to the tax office so they can work out if you are due to pay tax. Currently the tax threshold is £10,600 so you are allowed to ear this before having to pay tax.
You can of course work out your tax yourself, but many people opt to employ an accountancy firm to do this for them. You will need to make sure you have kept all receipts, invoices and a note of mileage to enable you or your accountant to work out your tax return.