Self-Employed and Small Businesses Self Assessment Tax Return Guide

What were the reasons why you missed your tax return last year? Your laptop broke? Your dog ate all of the tax returns and all of your reminders? Whatever your excuses were, we want to help you steer clear from more awful excuses this January.

When is the Self Assessment tax return deadline?

If you’ve already done yours or if you met the paper deadline on 31stOctober, don’t panic! However, if you currently haven’t filed your tax return online, it’s important to do so before the 31stJanuary deadline to avoid a fine.

Check if you need to send a Self Assessment tax return

If you’re unsure whether you need to file for a self assessment tax return, read our checklist of assumptions below.

  • You have one self-employment (one business)

  • You’re using the cash basis, which is a very simple way of doing a UK tax return (this isn’t for everyone so seek advice from an accountant)

  • You have a fictitious turnover of £30,000 a year with £10,000 business expenses and capital expenditure combined which gives a taxable profit of £20,000

  • There’s nothing unusual about your tax situation

  • You’ve received your letter from HMRC

  • You already have your Government Gateway Login (if you’ve left this until the last minute, speak to HMRC very quickly as this can take some time to sort out)

If any of the above applies to you, you will need to make time to prepare filling your online tax return. This includes Income Tax, Dividend Tax, Corporation Tax and VAT depending on your business type.

If you’re still unsure, check out this useful tool from HMRC. If you’re in need of accountancy advice, we recommend getting a good accountant as they will probably help you save more money than they’ll charge you.

Get started with your Self Assessment tax return

According to figures 36% of self assessment taxpayers under-reported their taxes, whilst 60% of self-employed people were underpaid.

Self-employment has been one key factor to the unemployment rate dropping below 4% for the first time in decades in 2017, with the UK labour market growing from 3.3 million to 4.8 million. The rapid growth may relate to the increased number of fines self-employed people are receiving as they are making silly mistakes, possibly due to being informed incorrectly. Consequently, we have prepared some quick, useful links below to give you some guidance on how to get started.



The deadline for online tax returns is 31st January 2020.

  • You must keep a record of all your income and expenses

  • Use accounting apps to help you keep track

  • You’ll need your UTR (unique taxpayer reference) number (printed on letters from HMRC regarding your tax return).

  • For any additional information, see here.

If you’re a small business, don’t forget about these costs you can claim back on:

  • Salary costs: Contractors, Salaries

  • Office costs: Rent, Insurance, Stationery

  • Transport costs: Petrol, Train, Parking

  • Training Course: Must be related to your business but not about how to start a new business

  • Advertising & Marketing: Free Samples, Website cost and Mailshots

  • Clothing: Protective gear, costumes (we all know a few clowns in the industry ????)

  • Reselling Goods: Materials, producing cost of goods

Recent changes you need to be aware of

HMRC are slowly moving all Tax related functions digital as part of their Making Tax Digital campaign which they have put parts of on hold. If you’re a business that has to pay VAT, then you would need to submit this online.

Please note we’re not consultants. This blog is intended as a guide, you should do your own research and always follow HMRC requirements.