Statutory Audit or Voluntary Audit: Which One Does Your UK Business Actually Need? Plenty of UK business owners hear the word "audit" and assume it only applies once a company hits a certain size. That's true for one kind of audit, but not the other, and mixing the two up leads to some expensive guesswork. Some businesses that legally don't need an audit end up commissioning one anyway, because it opens doors a set of unaudited accounts never will. Others assume they're safely under the radar when their numbers have quietly moved them into audit territory without anyone checking. Here's how the two differ, how UK businesses choose between audit companies, and how to work out where your own company sits.
What Makes an Audit "Statutory" in the First Place? A statutory audit is one your company is legally required to have, set out under the Companies Act 2006. Whether you fall into that category comes down to three numbers: your annual turnover, your balance sheet total, and your average number of employees. Cross the thresholds on enough of those measures and a statutory audit stops being optional. It's worth remembering these thresholds aren't fixed forever. They get reviewed periodically, and the government adjusted them again in April 2025, which pulled a meaningful number of previously exempt companies back into audit territory almost overnight. A business that checked its exemption status two or three years ago and never looked again could easily be operating on outdated assumptions. Our guide to current UK audit exemption thresholds walks through exactly where those limits sit today. There's also a lesser-known trigger that has nothing to do with size. Shareholders holding at least 10% of any class of shares in a company can formally request a statutory audit, even when the company would otherwise qualify as exempt. It doesn't come up often, but it's a real mechanism, not a theoretical one.
What Is a Voluntary Audit, and Why Would Anyone Choose One? A voluntary audit is exactly what it sounds like: a company that isn't legally required to have an audit chooses to have one anyway. On paper this looks like extra cost for no legal benefit, which is probably why so many smaller businesses never consider it. In practice, the businesses that choose voluntary audits tend to be the ones actively trying to grow. Banks weighing up a loan application, investors deciding whether to back a company, and larger clients sizing up a supplier before signing a multi-year contract all tend to trust audited figures more readily than unaudited ones. It doesn't matter that the law didn't require the audit. What
matters to them is that an independent third party has already checked the numbers add up. For a business chasing funding, an investment round, or a contract with a bigger client, that's often the entire point of commissioning proper financial audit services in the first place. There's a second, quieter reason businesses go voluntary: internal visibility. A financial audit doesn't just confirm your figures are accurate, it tends to surface weak spots in processes and controls that nobody inside the business had noticed yet. That overlaps closely with what internal audit services are designed to do on an ongoing basis, rather than as a one-off exercise tied to statutory reporting.
What Does a Financial Audit Actually Involve? Whether it's statutory or voluntary, the underlying mechanics of a financial audit don't change much. An independent auditor examines your accounting records, tests a sample of transactions against real supporting evidence, and checks that your figures have been prepared in line with current UK accounting standards. The process ends with a formal written opinion confirming whether your accounts give a true and fair view of the company's financial position, which is the document a bank, investor, or shareholder will actually rely on. If you want the full step-by-step breakdown of what happens once an audit is underway, our earlier piece on what actually happens during a UK business audit covers the whole process from the engagement letter through to the final opinion. What does shift between statutory and voluntary work is the framing. A statutory audit is carried out because the law says it must happen. A voluntary one is scoped around whatever the business is actually trying to achieve, whether that's satisfying a specific lender's conditions or preparing the company for a sale. The audit itself is no less rigorous just because it wasn't legally required.
How Internal Audit Services Fit Into the Bigger Picture It's easy to lump internal audit services in with statutory or voluntary audits, but they serve a different purpose entirely. A financial audit produces a formal opinion for people outside the business. Internal audit work has no external audience at all. It's an ongoing, deliberate check on how well your own controls and processes are working, designed to catch fraud risk, inefficiency, or weak segregation of duties before they turn into something more expensive.
Businesses that invest in internal audit services tend to do so regardless of whether they're legally required to have a statutory audit, because the value is entirely internal. A well-run internal audit programme often ends up making any future statutory or voluntary audit faster too, since many of the same control weaknesses would otherwise surface during external fieldwork anyway. A handful of common assumptions still trip businesses up here, which our piece on audit myths UK business owners still believe covers in more detail.
How Do You Actually Work Out Which One Applies to You? Start with the numbers. Pull your most recent turnover, balance sheet total, and average headcount, and check them against the current thresholds rather than relying on memory of where you sat last time you looked. If you're close to any of the limits, or you've grown meaningfully through new contracts, an acquisition, or bringing new entities into a group structure, it's worth treating your exemption status as something to reconfirm annually rather than assume, alongside your statutory and management accounts filings. If you're comfortably under the thresholds, the real question shifts from "do I have to" to "would it help." That depends entirely on what you're trying to do with your business over the next year or two. Chasing external funding, preparing for a sale, or trying to win contracts with larger, more risk-averse clients all tip the answer towards yes. Running a stable, self-financed business with no near-term plans to bring in outside money tips it towards no, at least for now.
Choosing Between Audit Companies in the UK Once you've decided an audit makes sense, either statutory or voluntary, the next decision is who actually carries it out. Not every firm offering "audit services" is legally permitted to sign off a statutory audit. In the UK, only auditors registered with a recognised supervisory body, such as the ACCA or ICAEW, and regulated under standards set by the Financial Reporting Council, can carry out this work. When comparing audit companies in UK, it's worth checking a few practical things beyond the headline price. Does the firm understand your specific sector, whether that's property, healthcare, professional services, or something more niche? Will you get a named contact who actually knows your business, rather than being passed between departments? Will findings be explained in plain English, or buried in technical language that needs translating afterwards? And can the firm support you beyond the audit itself, with tax, company secretarial work, or business valuations, so your audit doesn't sit in isolation from everything else affecting your accounts?
The Cost of Getting This Wrong Filing accounts as though you're exempt when you've actually crossed the threshold isn't a paperwork technicality, it's a compliance failure that Companies House can act on. On the other end, businesses that could genuinely benefit from a voluntary audit but never consider one sometimes lose out on funding or contracts without ever realising an audit was the missing piece.
Either way, the fix is the same: check your actual position rather than working from an assumption that might be years out of date, and treat the statutory-versus-voluntary decision as something worth revisiting properly rather than settling once and forgetting about it.
A Quick Way to Think About It If in doubt, work through it in this order: check your numbers against the current thresholds first, work out whether a shareholder could formally request an audit even if you're exempt, and only then move on to the voluntary question of whether audited figures would actually
help you raise funding, land a bigger client, or prepare for a sale. Skipping straight to "we're too small to worry about this" is usually where businesses come unstuck.
Not Sure Where Your Business Stands? Whether you're trying to confirm your exemption status, weighing up a voluntary audit to help with funding, or looking to compare audit companies in UK properly before committing to one, we're happy to talk it through with no jargon and no pressure. Call us on 0207 183 5956, visit www.bsassociate.co.uk, or explore our full Audit Assurance & Services page.
Frequently Asked Questions What's the real difference between a statutory audit and a voluntary audit? A statutory audit is legally required once your company crosses specific turnover, balance sheet, and employee thresholds. A voluntary audit is chosen by a business that doesn't meet those thresholds, usually to build credibility with lenders, investors, or larger clients. Can a shareholder force an audit even if my company is exempt? Yes. Shareholders holding at least 10% of any class of shares can formally request a statutory audit, regardless of whether the company would otherwise qualify as exempt. Is a voluntary audit less thorough than a statutory one? No. The underlying process, testing transactions, checking accounting standards, and producing a formal opinion, is the same whether the audit was legally required or chosen voluntarily. How do internal audit services differ from a financial audit? A financial audit produces a formal opinion for external parties like banks and investors. Internal audit services have no external audience and focus on checking your own processes and controls on an ongoing basis. How do I choose between audit companies in the UK? Check that the firm is registered with a recognised body such as the ACCA or ICAEW, understands your sector, gives you a named contact, and can support you beyond the audit itself with tax or company secretarial work. Who can help me work out my audit position? Brayan & Spencer Associates offers tailored audit assurance services for UK businesses of all sizes. Call 0207 183 5956 or visit www.bsassociate.co.uk to speak with our team.