Your first Self Assessment return is a set of questions about one tax year, answered once, and then sent. It feels heavy because it is unfamiliar, not because it is complicated. If you take it in order and gather your figures before you sit down, it is a calm afternoon's work.
Do you need to file one
You usually need a Self Assessment return if you are self-employed as a sole trader, if you are a landlord receiving rental income, or if you have income that is not taxed at source, such as dividends or untaxed savings interest. If you are not sure, it is worth a short call rather than guessing.
If you have started working for yourself, you need to tell HMRC and register for Self Assessment by 5 October after the tax year in which you started. Miss that date and the return is still due, but the process gets less comfortable.
What you need to gather
Before you open the form, collect the things it will ask for. A little preparation removes most of the friction.
- Your Unique Taxpayer Reference, or UTR, and your National Insurance number.
- Your income for the year, whether that is self-employed turnover, rental income or both.
- Records of business costs and expenses you want to claim.
- Any other income, such as a part-time job, dividends or savings interest.
- Details of pension contributions or Gift Aid payments if you made them.
Keep the records behind the figures. If HMRC asks a question later, the numbers need to hold up, so store receipts and bank statements together and keep them for the required period.
The deadlines that matter
For a paper return, the deadline is 31 October after the end of the tax year. For an online return, it is 31 January. Filing online also lets you see your bill and pay it in the same place.
If you owe tax, payments on account can come with it. These are advance payments towards next year's bill, due on 31 January and 31 July. A first return often brings the January payment plus the first payment on account in one go, which can surprise people, so it is worth knowing before the date rather than after.
Do it once, do it well
The first return is the slowest. Once it is filed, most of the structure carries into the next year, and a simple record-keeping habit through the year turns the next one into an hour's tidy-up. If your circumstances change, a new job, a house move, a second income, note it as it happens, because small notes are far easier than a box of receipts in January.
If this all sounds manageable but you would rather it were simply done, that is exactly what a fixed-fee package is for. Your accountant gathers the figures, prepares the return and files it before the deadline, and you get a reply within one working day when you have a question.
