Take the stress out of self-employment with online accounting support built around you
Running your own business is rewarding, but managing the finances can be confusing and time-consuming.
From tracking expenses to filing tax returns, it’s easy to feel overwhelmed. That’s why Simplex offers tailored support for self-employed business owners who want to stay on top of their finances without the hassle. We’re award-winning online accountants for self-employed business owners across the UK, offering unlimited support, expert advice and clear monthly pricing.
Save Time Every Week
We take care of bookkeeping, tax submissions and payroll. Cloud-based tools mean less admin for you.
Stay Tax Ready Year Round
No more scrambling at year end. We keep you up to date with reminders, advice and timely submissions.
Get Personal Support
Call, WhatsApp or email anytime. With Simplex you always speak to someone who knows your business and gives clear helpful advice.

What to Expect from Our Online Accounting Service
We help self-employed business owners take control of their finances with less stress. Whether you’re just starting out or scaling up, we provide support that grows with you.
✅ Bookkeeping, payroll and tax returns handled for you
✅ Fixed monthly pricing with no surprise bills
✅ Access to real-time figures and your accountant
✅ Unlimited communication by phone, text or email
✅ Personalised support tailored to your business goals
With Simplex, you’ll always know where you stand and never feel like you’re doing it alone.
“I’m sure I’m not the only small business to leave self-assessment to the last minute. I contacted Lucy and she was so helpful and determined to get my books in on time.”
June, Sole Trader
Support That Goes Beyond the Numbers
At Simplex, we go beyond basic accounting. We get to know your business, your goals, and what success looks like to you. You’ll have a dedicated accountant who’s proactive, responsive and on your side.


Why Businesses Choose Simplex
✨ All-in-one accounting and payroll in one place
✨ Save hours every month with less admin
✨ Get tax returns filed accurately and on time
✨ Clear monthly pricing with no hidden fees
✨ Speak to real people who know your business
Simplex gives you more time, less stress, and support you can rely on.
“This service is state of the art – using all apps and synced devices to make the usually laborious job of keeping track of income and expenditure an absolute doddle.”
Tony, Film Producer
Smart Tools, Simple Setup
We use simple, reliable tools to take the pressure off your payroll. We set everything up for you, walk you through how it works, and stay by your side whenever you need help.
Xero
Your live invoicing dashboard.
Send, track and match invoices in real time, with everything synced to your accounts automatically.
dext
Receipts and bills, sorted.
Snap a photo or forward an email. We handle the rest so nothing gets lost and your records stay complete.
brightpay
Your payroll, fully managed.
Payslips, reports and filings are all taken care of, so you stay compliant and everything runs on time.
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!
For self-employed individuals, accountant fees typically start from £25 per month, depending on the level of support you need. Whether you just need help with a tax return or ongoing support throughout the year, there’s a plan to suit your business. We offer flexible packages that keep things simple and affordable, so you only pay for what you actually need.
Yes. An accountant can save you time, help you claim the right expenses, and make sure you stay compliant with HMRC. If you’re juggling everything yourself, it’s a smart investment. We support self-employed clients across the UK with practical advice and ongoing support to keep your finances in good shape.
Yes, you can. Online accountants offer all the same services as traditional ones, with the added convenience of working remotely. We support clients across the UK using secure systems, cloud accounting, and regular check-ins, so you can manage your finances from anywhere with confidence.
Using Xero is a great step, but it doesn’t replace the value of an accountant. We help clients use Xero properly, check that everything’s accurate, and provide tailored advice based on your figures. Having expert support means fewer errors and better results when it comes to tax time.
Yes. Self-assessment can be confusing and time-consuming if you’re not confident with tax rules. An accountant will make sure everything is correct, help you claim the right expenses, and reduce the risk of penalties. We make the process simple and fully online, so it’s easy to stay on top of your obligations.
A self-assessment tax return starts from £25, but the cost depends on how simple or complex your situation is. If you have multiple income streams or need extra support, a monthly plan may be more cost-effective. We offer fixed-fee options, so you always know what’s included and there are no hidden surprises.

