Top 10 Tips for completing your Self-Assessment Tax Return

It's that time of year again, and the deadline for filing your self-assessment tax return online is looming. Here are my top ten tips for getting it right.

1. If you make assumptions, tell HMRC about it in the additional information space. For example, if you're not sure 100% sure whether a cost is allowable or not, state that you've claimed it and the reason why. Wherever possible it's always best to consult HMRC first if in doubt, but if there is no clear answer, declare it instead.

2. Get professional advice if your affairs are complex. This complies with HMRC's new penalty regime which says that you should take responsibility for your tax returns and if you are not confident of completing your own return, ask for professional help.

3. Do it early so that you know if you're due a refund, or calculate how much to start setting aside to pay the bill in January and July.

4. Classify expenses correctly. If you put repairs in the depreciation box for example, they will be disallowed.

5. Don't forget to include all supplementary pages. So if you were employed in the tax year as well as self-employed, you will need to fill in an employment page, even though your tax has already been deducted via PAYE.

6. Avoid using estimates - this could point to the fact your records aren't very good.

7. Include all figures on the tax return itself. Don't just send in copy accounts and expect HMRC to put the figures in the right places.

8. Deduct personal use. If you use broadband for business and personal use, then you must deduct the relevant percentage of personal use from your expense claim. Best practice is to keep a log of all personal use. Check out our free helpsheet on which expenses you can claim here.

9.  Include any brought forward losses or pre-trading expenditure to make sure your tax bill is correct.  HMRC will not allocate brought forward losses for you, so to make the most of any tax relief due you must put this in yourself.

10. Get it in on time (31 Jan for online submissions). Failure to do so will automatically incur a £100 fine and interest on late tax. If you don't complete your tax return on time, I recommend you estimate what your tax bill will be and pay it to avoid the interest charge.

Robyn Hughes is a chartered tax advisor and Director at HSJ Accountants.

If you would like more advice on your self assessmnet tax return then please call Robyn on 0845 365 1000 or email Robyn here.