Save Tax, Stay Stress-Free, and Grow with Confidence
Running your own business as a sole trader can feel overwhelming, especially when it comes to tax. From deadlines and self-assessments to knowing what you can claim, it is easy to worry about getting it wrong or paying more than you should. At Simplex, we act as your dedicated sole trader tax accountant, handling everything for you while giving clear and friendly support. You will always know where you stand, what to do next, and how to keep more of your hard-earned money.
We Handle Everything
From self-assessment tax returns to ongoing support, we take care of the details so you can focus on running your business.
Reduce Your Tax Bill
We make sure you claim every allowable expense and relief available to sole traders. No guesswork and no missed opportunities.
Support Whenever You Need It
Message, call or email us anytime and get clear, reliable support whenever you need it, without delays, confusion, or extra charges.
Why businesses choose Simplex
Dedicated support for your sole trader business
Whether you are just starting out or already established, everything is handled in a way that feels simple, clear, and easy to manage.
Clear and easy to understand
Your finances are kept straightforward and explained in plain English, so you always know where you stand without confusion.
Simple systems that save you time
We use modern tools to streamline your accounting and only introduce what is genuinely useful, so you spend less time on admin.
Fast, responsive communication
You can always get in touch when you need to, with a 48-hour response guarantee and support available from 9 am to 6 pm.
All your accounting, done for you
Everything you need to stay organised, compliant, and in control of your finances. We make sure everything is handled properly, deadlines are met, and your records stay clear and easy to manage.
✅ Self-assessment tax returns prepared and submitted
✅ Ongoing support to keep your records accurate
✅ Clear tracking of income and expenses
✅ Tax planning to help reduce your bill
✅ Support if you register for VAT
✅ Payroll support using BrightPay if needed
✅ Unlimited support via call, text, or email
We keep everything simple, efficient, and easy to stay on top of.
“Simplex have been an integral part of our new business, they have helped us navigate business set-up, HMRC & tax and accounting. Professional, knowledgeable, dynamic and local. We couldn’t ask for more.“
Neil, Contractor
More than just tax returns…
Running a sole trader business is about more than meeting deadlines and submitting returns. You want everything handled properly, kept organised, and easy to stay on top of without unnecessary stress.
At Simplex, your finances are managed in a way that works for your business. Whether you are just getting started or already growing, you get consistent support, clear communication, and a setup that keeps everything running smoothly.
You will always know where things stand, what has been taken care of, and that nothing is being missed.
Simple, digital, and built around you
Work with your accountant in a way that fits your day. No meetings you do not need, no paperwork delays, and no complicated systems. Simplex is fully digital and remote, making it easy to manage your sole trader finances wherever you are.
Everything is handled online, from sharing documents to staying in touch. You can send messages, ask questions, and get what you need without interrupting your workflow.
You still get the same level of support, just delivered in a faster and more flexible way that works around you.
“Simplex are super easy to work with. I love that I have a portal to track all documents and paperwork that need my attention. Everything else just seems to run in the background so I can focus on my business”
Jordan, Designer
Simple Accounting
We set you up with easy, reliable tools so your finances stay organised without adding to your to-do list. Everything is customised for the way you work, and we’re always here if you need help.
Xero
Stay organised without spreadsheets.
See your income, expenses and invoices in one place, always up to date and ready when you need it.
dext
No more chasing receipts.
Snap a photo or forward an email, and your bills and receipts are stored, sorted and matched to your accounts.
brightpay
Stress-free payroll.
Payslips, pensions and submissions are taken care of, always on time and fully compliant with HMRC
Getting Started is Easy!
We’ve made it simple for you to get the help you need:
Book a Free Call
Tell us about your business and what you need.
Send Your Info
Share your financial details securely online.
We Do the Work
We’ll sort your accounts and keep everything up to date.
Stay in Control
Get updates and support, so you always know where you stand.
Book your free discovery call! It will only take a minute
Time to Switch Accountants?
You don’t need to stay stuck with support that’s slow or confusing. Switching to Simplex is smooth and handled for you.
Seamless Transfer
We contact your previous accountant and securely move everything over, CIS, VAT, payroll and more.
No Disruption
Your accounts stay up to date while we handle the switch, so nothing gets missed.
A Fresh Start
We review your numbers, identify gaps, and get you set up with a clear plan that works for you.
Ready to switch? Let’s make it happen.
Helpful Resources
Your Questions, Answered
We know you might have some questions, and we’re here to make everything as clear and straightforward as possible. If you need more information, don’t hesitate to reach out—we’re always happy to help!
As a sole trader in the UK, you’ll pay Income Tax on your profits, plus National Insurance. The amount depends on how much you earn after expenses. For example, profits above your Personal Allowance are taxed at 20%, 40%, or 45%. Planning ahead can make a big difference, so working with an accountant helps ensure you’re not overpaying and everything is filed correctly.
From April 2026, Making Tax Digital for Income Tax will apply to more sole traders. This means keeping digital records and submitting quarterly updates to HMRC. It’s a big shift from the annual Self Assessment system. Getting set up early with the right software, along with guidance from an accountant, can make the transition smooth and keep you compliant.
While being a sole trader is simple, there are a few downsides. You’re personally liable for debts, which can be risky. Tax planning options are more limited than with a limited company. It can also be harder to raise finance, and you may pay more tax as profits grow. Finally, there’s less perceived credibility. An accountant can help you decide if switching structure makes sense.
Yes, if you earn over £1,000 in a tax year, you must register with HMRC and may need to pay tax. You’ll pay Income Tax on your profits and usually National Insurance contributions too. Even if your earnings are low, it’s important to check your obligations. Staying organised with your records makes filing easier and helps avoid penalties.
Yes, you must register as self-employed with HMRC by 5 October after the end of the tax year you started trading. This ensures you’re set up for Self Assessment and paying the right tax. It’s a straightforward process, but getting it right from the start is key. Many business owners choose an accountant to handle registration and ongoing filings for peace of mind.
