CrestWell AccountantsSelf Assessment Tax Returns
CrestWell Accountants prepares and files personal Self Assessment tax returns with HMRC, from Crawley, West Sussex. We gather your income and allowable expenses, work out the tax due, file the return before the deadline and tell you what to pay and when, with the work prepared and checked by an ICAEW Chartered Accountant.
Checked by Omar Ahmed Khan ACA, Founder and Principal, on .
Read the transcript
Rules for filing Self Assessment tax returns are changing. Under Making Tax Digital, majority of the sole trade businesses will have to report their income on a quarterly basis. Therefore, it's absolutely critical that the accurate information is reported in these quarterly returns.
So whether you have sole trade income, dividend income or rental property income, or you may have sold your shares or rental property which are subject to capital gains tax. We deal with them all. We make sure we prepare your tax return accurately and file them on time. If you deal with the trust we also file trust tax returns too. Wherever your situation may be you hand us the documents and we'll take care of the rest.
If you need to complete a Self Assessment tax return, we can prepare and file it for you.
Who needs to file a return
HMRC uses Self Assessment to collect Income Tax that has not already been taken through PAYE. You may need to file a return if, for example, you:
- are self-employed as a sole trader, with income above HMRC's trading allowance
- are a partner in a business partnership
- receive rental income from property
- have significant savings, investment or dividend income that has not been taxed at source
- have sold assets and need to report a capital gain
- have income from abroad
If you are not sure whether you need to file, we can tell you.
What we do
- Collect the information needed for your return, including income, allowable expenses and any reliefs you are entitled to
- Prepare your return and calculate the tax due
- Go through it with you before it is submitted
- File the return online with HMRC
- Tell you how much to pay, when, and whether payments on account apply
Key dates
The tax year runs from 6 April to 5 April. For each tax year:
- 5 October: the deadline to register for Self Assessment if you have not filed before
- 31 October: the deadline for paper returns
- 31 January: the deadline for online returns, and for paying any tax owed for the year, along with the first payment on account for the following year where it applies
- 31 July: the second payment on account, where it applies
HMRC charges an automatic £100 penalty for a late return, with further penalties and interest the longer it goes unpaid or unfiled.
Making Tax Digital for Income Tax
From April 2026, sole traders and landlords with qualifying income above £50,000 must keep digital records and send quarterly updates to HMRC through compatible software, and the threshold falls to £30,000 from April 2027. If this applies to you, we can explain what it means for your records and your return.
What we need from you
Your Unique Taxpayer Reference, details of your income for the year, records of any expenses you want to claim, and any relevant statements, such as P60s, bank interest or dividend statements. We will send you a simple checklist.
Getting started
To ask about a Self Assessment return, get in touch and choose Self Assessment Tax Returns from the list. We will reply within one business day.
What our clients say
- Google review
Undoubtedly I could not have asked for another more professional, accurate and conscientious accountant to handle my 2025/26 income tax return. The way Omar handled a fairly complicated affair (considering I have local income, pension and overseas income), was an example in patience, stubbornness and detail - he made sure I got everything right, and had the documentation to support it all! On top of it all, I found Omar's pricing to be both fair and highly competitive for the high standard of work done. We'll definitely be back with Crestwell and Omar next year.
Adrian Stevens (opens the review on Google in a new tab) - Google review
Capital gains
I sold a property this year and had no idea where to start with capital gains tax. Omar at CrestWell Accountants and Advisors took it off my hands. Omar worked out the gain, included the costs I was allowed to claim and used my allowances, which kept the bill down. It was reported to HMRC on time and I was told exactly what to pay and when. Every step was explained so I knew what was going on. If you have sold a property and aren't sure what you owe, go to Omar.
Josh Media (opens the review on Google in a new tab)
Common questions
When is the Self Assessment deadline?
- For online returns, the deadline is 31 January after the end of the tax year, which runs to 5 April. Paper returns are due earlier, by 31 October. Any tax owed for the year is also due by 31 January.
What happens if I file late?
- HMRC charges an automatic £100 penalty if your return is even one day late, with further penalties if it is later still, and interest on any tax paid late.
Ready to take control of your finances?
Book a free, no-obligation consultation and discover exactly how CrestWell can help. It is simply an honest conversation about your business.