Self assessment

It's a common misconception that you only need to file a Tax Return if you are self-employed in fact you'll need to file a tax return if, in the last tax year:

you were self-employed - you can deduct allowable expenses
you got £2,500 or more in untaxed income, eg from renting out a property or savings and investments
your savings or investment income was £10,000 or more before tax
you made profits from selling things like shares, a second home or other chargeable assets and need to pay Capital Gains Tax
you were a company director - unless it was for a non-profit organisation (eg a charity) and you didn't get any pay or benefits, like a company car
your income (or your partner's) was over £50,000 and one of you claimed Child Benefit
you had income from abroad that you needed to pay tax on
you lived abroad and had a UK income
you got dividends from shares and you're a higher or additional rate taxpayer
your income was over £100,000
you were a trustee of a trust or registered pension scheme

Certain other people may need to send a return (e.g religious ministers or Lloyd's underwriters).

K & R can help with compliance to avoid any penalties but also offer sensible tax planning to reduce any tax liabilities.