What does an accountant actually do? A simple guide for UK businesses

Plenty of business owners know they need an accountant, but aren't always sure what one actually does. Beyond tax returns and spreadsheets, an accountant is a financial partner who keeps you compliant, saves you tax, and helps you make better decisions about the business.

This guide breaks down what accountants really do for UK businesses, in plain English, so you can decide what you need and what a good one is worth.

What does an accountant do? The short answer

An accountant records, checks and reports on the money moving through a business. In practice that covers six things:

1. Keeping the bookkeeping accurate and up to date.
2. Preparing and filing statutory accounts with Companies House.
3. Filing tax returns (VAT, corporation tax, Self Assessment) with HMRC.
4. Running payroll and pension submissions.
5. Producing management reports so you understand how the business is performing.
6. Advising you on tax, cash flow and growth decisions.

The value isn't in any single task. It's in having someone who joins them up so nothing slips through the cracks.

More than just number crunching

The stereotype is an accountant who appears once a year, files a return and disappears. A modern small business accountant works differently. They stay close to the numbers month by month, flag issues before they become problems, and give you the information you need to make confident decisions.

That shift matters because HMRC has moved to real-time reporting. Under Making Tax Digital, VAT-registered businesses already keep digital records and file quarterly, and Self Assessment is following. Once-a-year accounting is on the way out.

The six things a good accountant handles

1. Bookkeeping and records

Every transaction the business makes needs to be recorded accurately and in the right category. Accountants either do the bookkeeping themselves or make sure your in-house records are clean enough to work from. Get this wrong and everything downstream (VAT, accounts, tax) is wrong too.

2. Tax compliance

From VAT returns to corporation tax and Self Assessment, accountants make sure your business meets HMRC deadlines and rules. A missed VAT return costs at least £200 in penalties. A late set of company accounts costs £150 to £1,500. Compliance isn't glamorous, but it protects real money.

3. Payroll and pensions

If you employ anyone, payroll has to run every pay period with the right tax codes, National Insurance, statutory pay and pension contributions submitted to HMRC and the pension provider. Getting it wrong upsets staff and triggers HMRC letters.

4. Financial reporting

Accountants prepare statutory year-end accounts for Companies House and HMRC, and management accounts during the year so you can see profit, cash and margins as they happen instead of nine months late.

5. Budgeting and cash flow

Cash is what actually keeps a business alive. Accountants build simple forecasts, spot the months where cash tightens up, and help you plan for VAT and corporation tax bills before they land.

6. Advice and decisions

The best accountants earn their fee here: reviewing how you draw money from the business, whether a new hire is affordable, what a price rise means for the bottom line, or how to structure a purchase to be tax efficient.

Accountant vs bookkeeper: what's the difference?

Bookkeepers record the transactions. Accountants interpret them and file the returns. Small businesses need both, which is why most modern firms bundle them into a single fixed monthly fee rather than making you juggle two suppliers.

If you already have a good bookkeeper, an accountant reviews their work, prepares the statutory pieces and handles advice. If you don't, look for a firm that does both under one roof.

When should you hire an accountant?

There's rarely a bad time, but the common trigger points are:

• You've registered a limited company. Statutory filings kick in immediately and the penalties for getting them wrong are steep.
• Turnover is heading toward £90,000. That's the VAT threshold, and you want an accountant in place before you have to register.
• You've hired your first employee. Payroll, PAYE and pensions all start.
• You're about to raise funding or apply for a loan. Lenders and investors want clean numbers.
• You dread Self Assessment. If tax season is stressful, that's the problem an accountant solves first.

The earlier you bring someone in, the less time is spent untangling old mistakes.

How much does an accountant cost in the UK?

Fixed monthly fees are now the norm. A rough guide for a UK small business:

• Sole trader: £30 to £60 a month for bookkeeping tidy-up and Self Assessment.
• Limited company (early stage): £100 to £250 a month covering accounts, corporation tax, Self Assessment for one director and ongoing support.
• Growing company: £300+ a month bundling bookkeeping, VAT, payroll, management accounts and advisory calls.

A good accountant usually pays for themselves by cleaning up your tax position, catching errors and freeing up your time.

How to choose the right accountant

Not every firm suits every business. When you're comparing:

• Qualifications. Look for chartered or certified status through ACCA, ICAEW or CIMA.
• Fixed fees, not hourly billing. You want to know what the year costs before it starts.
• Cloud-first working. They should be fluent in Xero, QuickBooks or FreeAgent, not asking you to post them a shoebox of receipts.
• Response time. Ask how quickly they reply to an email or a WhatsApp message. This is where most relationships break down.
• Range. If they can't do bookkeeping, VAT and payroll under one roof, you'll end up managing multiple suppliers.

What an accountant does month by month

Annual work is only part of the picture. A typical month with a modern firm looks like this: bookkeeping is reconciled and queries cleared, payroll is run and submitted to HMRC, VAT is prepared and filed where the quarter falls, and a short reporting pack lands showing profit, cash and anything unusual. Quarterly, there is a conversation about tax set-aside, pricing and whatever decision is next.

That rhythm is what separates an accountant who files things from one who is useful. It is also what management accounts are for: seeing the trading position while you can still act on it, rather than nine months after the year end.

Accountant versus doing it yourself

Plenty of sole traders file their own Self Assessment perfectly well. The calculation is manageable and the software helps. The maths changes once you incorporate.

A limited company has statutory accounts, a corporation tax return, a confirmation statement and at least one director Self Assessment, all with their own deadlines and their own automatic penalties. Add VAT and payroll and the admin becomes a job in itself. Doing it yourself is possible, but the time cost is real and the penalty risk is asymmetric: getting it right saves nothing, getting it wrong costs hundreds.

The honest test is whether an hour spent on the books earns you more than an hour spent on the business. For most owners it does not.

What to expect in the first ninety days

A good onboarding follows a pattern. In the first month, the accountant collects your records, takes over as agent with HMRC, writes to your previous accountant if there is one, and gets your software connected. In the second, the historic bookkeeping is brought up to date and any errors in prior filings are flagged. By the third, reporting is running on a normal cycle and you should have had at least one conversation about tax planning.

If you are three months in and have only had invoices, something has gone wrong. Switching is far easier than most people expect, and changing accountant does not require an awkward conversation with the outgoing firm.

What an accountant will not do

It is worth being clear about the limits. An accountant will not run your business, chase your customers for payment unless you ask them to as a separate service, or make your numbers say something they do not. They will not provide regulated investment advice, and they will not sign off aggressive schemes that leave you exposed if HMRC looks closely.

A firm promising outcomes that sound too good usually is. The value is in doing ordinary things properly and consistently.

What good accounting feels like

You know it's working when tax deadlines stop feeling like emergencies, you can answer "how's the business doing?" in a sentence, and you have someone to call before a big decision instead of after it.

Accountants do far more than file tax returns. They're the trusted advisors who keep you compliant, help you make better decisions and give you back the headspace to run the business. If that's what you're after, have a look at how we work or book a chat.