Last updated Apr 03, 2024 and written by Tom Richardson

How To File Your First Self Assessment

The words “Self Assessment” tend to send a shiver down the spines of sole traders and limited company directors. Getting yourself registered, getting your records in order, and filing with HMRC before the 31st January deadline can be a stressful task, especially if you either leave it to the last minute, or if you’ve never filed one before.

The thing is, though, Self Assessments don’t need to be complicated. In fact, with a little forward planning, organisation, and the willingness to get it filed as early as possible, you can make the Self Assessment season feel like a stroll through the park.

So if you’re preparing to file your first Self Assessment, here’s everything you need to know.

Register with HMRC

You’ll need to register for Self Assessment with HMRC by 5th October after the end of the tax year where you are required to file a tax return – for example, if you need to file for the 20/2021 tax year, which ended on 5th April 2021, you should register by 5th October 2021. If you miss this deadline, you may have to pay a penalty.

You can register online, by post, or by phone. You’ll need your National Insurance number, as well as your personal and business details.

Once you’re registered, you’ll receive a Unique Taxpayer Reference (UTR) number in the post. You use your UTR to register for HMRC Online Services. HMRC will then send you a PIN number in the post to access Online Services where you can file your Self Assessment.

Keep digital records

One of the most important things you’ll need to do to file an accurate Self Assessment is to keep comprehensive records. The sorts of things you’ll need to keep records of include, but are not limited to:

  • Self-employed income (details of your invoices and business expenses)
  • Income from employment (a P60, or a P45 if you left a job within the tax year, and a P11D if appropriate)
  • Pensions contributions
  • Pension income
  • Payment on account if you’ve made any previously
  • Capital gains

You can find a complete run-down of the records you’ll need to keep in our Self Assessment guide, which is free to download and keep forever!

The easiest way to maintain these records is through online accounting software, which Crunch provides. Whether you sign up to one of our paid accountancy packages, or our free software, you can store your records and even ask Crunch to help file your Self Assessment for you!

How to fill in a Self Assessment tax return

We would always recommend filing your tax return as early as possible. This can be done anytime after the start of the new tax year, so long as you’ve registered and received your Unique Taxpayer Reference (UTR) code and log in details from HMRC.

Once you’ve logged into the HMRC online system, the process is not actually that daunting – so long as you’ve kept accurate records, which include all sales invoices and expense receipts. Essentially, you just need to fill out a form, and the system does the calculations for you!

How to pay the tax you owe

Once you’ve double-checked that all the information you’ve entered is correct and submitted your return, HMRC will tell you how much tax you owe. You can pay via Direct Debit or bank transfer (the full list of how you can pay is on the website). 

It’s worth noting that you cannot pay the tax you owe using a personal credit card.

An accountant can help, too!

If you already have an accountant, they can help you organise your records and complete the filing process – some will even file it for you. We certainly do!

If you’re without an accountant, or you’re with one who’ll nickel and dime you for every call and question, don’t forget to check out the accountancy packages we offer for limited companies and sole traders alike. Our paid packages include a team of expert accountants and client managers that are available whenever you need them to answer your questions – and you’ll never be asked to pay extra to speak to them.

You might also be interested in Crunch Free, our free online bookkeeping software available to access right now! Crunch Free is perfect for those businesses that are just starting out, who manage their own tax filings, or those who already have an accountant and need a secure system to record their expenses and send their invoices.

Whichever package you choose, Crunch can help you file your Self Assessment and take the stress off your shoulders. Head on over to our website and discover how Crunch can help simplify self-employment today!