Comptable Chartered Accountant · London & online

Accounts · VAT · Payroll · CIS · Tax

Careful, practical accountancy for businesses and the people who run them.

I'm John O'Sullivan, a chartered accountant. My team and I look after the accounts, VAT, payroll, CIS and tax of owner-managed businesses, directors and landlords, and we explain what the numbers mean in plain English.

  • ICAEW Chartered Accountant
  • UK, Australia and France experience
  • London and online

What we can help with

Straightforward compliance work done properly, and a second pair of eyes when something has gone wrong.

Accounts and bookkeeping

Year-end accounts, Companies House filings and bookkeeping on modern cloud software.

Learn more

VAT

Registration, returns and getting VAT problems with HMRC put right.

Learn more

Personal and director tax

Self Assessment, dividends and rental income, with clear advice on what you owe and when.

Learn more

Advice on difficult problems

Complex tax and accounting questions, cashflow worries and awkward HMRC correspondence.

Learn more

Payroll

Pay runs, payslips, HMRC submissions and pensions, so your team is paid correctly and on time.

Learn more

CIS for construction

For contractors and subcontractors: monthly CIS returns, statements and tax refunds.

Learn more

Making Tax Digital

Quarterly reporting to HMRC has started.

Sole traders and landlords with gross income over £50,000 now send quarterly updates. The threshold drops to £30,000 in April 2027 and £20,000 in April 2028. We set you up, send the updates and keep you on the right side of the deadlines.

How we can help

How we work

After a career running finance functions, I know what business owners actually need from their accountant: accurate work, delivered on time, with no jargon.

1

Practical problem-solving

We start from your situation and your goals, then find the simplest compliant way to get there.

2

Diligence

Every figure is checked and every deadline is tracked, so you are never surprised by a penalty.

3

Modern tools

Cloud accounting and secure online working, so we can work together wherever you are.

Our green approach

Accounting with a lighter footprint

Good accountancy and caring for the environment go together. This is how we keep our own impact small.

Cloud, not paper

Cloud accounting software and secure online document sharing keep paper to a minimum.

Meetings without the miles

Video and phone meetings mean fewer journeys, for you and for us.

Who we work with

Business owners and directors

Limited companies and small businesses that want reliable accounts, tidy VAT and tax advice they can act on.

Accounting for company directors

Individuals and landlords

Personal tax returns, rental income and one-off questions that need an experienced answer.

Tax help for landlords

What you can expect

We are at your side all year, not just at the deadline, so there are no nasty surprises.

Month by month

Your transactions are recorded accurately as you go, so you always have real-time management information.

Better systems

We keep an eye on your systems and processes and recommend changes that save you time, so you can focus on the business.

Filed with time to spare

Annual accounts are prepared and lodged with HMRC and Companies House early, giving you advance warning of any tax to pay.

A fixed monthly fee

You know our charges up front, so you can budget with confidence.

Getting started is simple

Thinking of changing accountant? It is easier than most people expect. Four steps and we do the heavy lifting.

  1. 1

    A free conversation

    We talk through your situation and what worries you. I tell you honestly whether we can help.

  2. 2

    A fixed monthly fee

    If we are a good fit, we agree one fee up front, so there are no surprise bills.

  3. 3

    A smooth handover

    We contact your previous accountant and collect the records we need, so you do not have to chase.

  4. 4

    Then, all year round

    Your books are kept up to date, deadlines are tracked and you hear from us before anything is due.

Book a free consultation

Common questions

What happens in the free consultation?

We talk through your situation, what is worrying you and what you need. I'll tell you honestly whether we can help and what the next step would be. There is no obligation to go further.

How much will it cost?

We charge a guaranteed monthly fee, agreed with you up front after the free consultation, so you know exactly what you will pay and can budget for it.

Do you only work with clients in London?

No. I have strong connections in London and am there regularly, so we can meet in person by arrangement. Most of the work is done securely online, so we can work together wherever you are.

What is Making Tax Digital and do I need to do anything?

If you are a sole trader or landlord with gross income above the threshold, you keep digital records and send HMRC a short update every quarter. If you charge VAT, you already file VAT digitally. We check whether you are affected, set it up and do the submissions for you. Read more

Do you handle payroll and the Construction Industry Scheme?

Yes. We run payroll for directors and small teams, including HMRC submissions and pension duties, and we handle CIS for contractors and subcontractors. Both can be included in your fixed monthly fee.

Which accounting software do you use?

We work with cloud software including Xero and QuickBooks, with Hubdoc and Receipt Bank (now Dext) to capture receipts and bills automatically. If you already use something else, tell us and we can talk it through.

Can you take over from my current accountant?

Yes. We handle the professional handover with your previous accountant and ask them for the records we need, so you don't have to chase.

I've missed a deadline or received a penalty. Can you help?

Yes, and the sooner you tell us the better. We'll find out exactly what has happened, explain your options and deal with HMRC or Companies House for you.

Dates worth knowing

Most penalties come from a missed date. These are the usual ones. Yours may differ, and when you work with us we track them for you.

  • 31 January
    Self Assessment return and any tax due for the previous tax year.
  • 31 July
    Second payment on account for the current tax year.
  • 9 months after year end
    Corporation tax payment, and your company accounts filed at Companies House (private companies).
  • 1 month and 7 days
    After each VAT quarter ends, for most businesses: return and payment.

Start with a free consultation

Tell us what you need. We'll tell you honestly whether and how we can help.

Get in touch
ICAEW Chartered Accountants Chartered Accountants Worldwide, Network Member