Best Audit Firms in Singapore: Big 4 vs Mid-Tier vs Boutique (2026)
By Lucas Seah, Founder of Excellence Singapore Group | Last Updated: June 2026
The best audit firm in Singapore is the one that matches your company’s size, industry, and budget, not simply the biggest name. The market splits into three tiers: the Big 4 (Deloitte, EY, KPMG, PwC) for listed companies and complex groups, mid-tier firms such as RSM and BDO for established SMEs, and boutique public accounting practices for small and owner-managed companies. Before you compare any of them, check whether you are legally required to have an audit at all, because many small companies are exempt.
This guide explains who can legally audit a Singapore company, how to tell whether you need an audit, what each firm tier costs and suits, and how to make the choice with confidence.
Key Takeaways
- Only a registered Public Accountant, working through an ACRA-registered public accounting entity, can sign a statutory audit in Singapore.
- Many small private companies are exempt from audit. A company qualifies as a small company if it meets at least 2 of 3 tests (revenue of S$10 million or less, total assets of S$10 million or less, 50 employees or fewer) across its last two financial years.
- The Big 4 suit listed companies and complex groups and typically charge S$15,000 or more. Mid-tier firms suit growing SMEs at roughly S$5,000 to S$15,000. Boutique firms serve small companies from roughly S$1,500 to S$5,000.
- ACRA announced a review of the audit-exemption thresholds in February 2026, but the current S$10 million thresholds remain in force as of mid-2026, with no change yet enacted.
- Match the firm to your company: brand recognition and global reach cost more, while partner attention is often higher at smaller firms.
First, Do You Even Need an Audit?
The most expensive audit is the one you did not need to buy. Under the Companies Act 1967, a private company is exempt from audit if it is a small company. It qualifies as a small company when it meets at least two of these three criteria for each of its last two consecutive financial years:
- Total annual revenue of S$10 million or less.
- Total assets of S$10 million or less.
- 50 employees or fewer.
If your company is part of a group, the group must also satisfy two of the three tests on a consolidated basis before you can claim the exemption. A dormant company is separately exempt under the Act. Public companies cannot use the small-company exemption.
For the full test, including how the two-year look-back and the group rules work, see our guide to audit requirements and the small company exemption. One change to watch: in February 2026 ACRA announced a consultation on raising the revenue and asset thresholds. As of mid-2026 the consultation has closed but no new thresholds have been enacted, so the S$10 million limits above still apply.
Who Can Legally Audit Your Company?
If you do need an audit, you cannot use just any accountant. A statutory audit must be performed by a Public Accountant who is registered with ACRA, practising through a registered public accounting entity. ACRA registers these auditors, inspects their work through its Practice Monitoring Programme, and publishes information on audit quality. The audit itself is carried out under the Singapore Standards on Auditing issued by the Institute of Singapore Chartered Accountants (ISCA).
The practical takeaway: before you engage any firm, confirm that the partner who will sign your report is a registered Public Accountant. A bookkeeper or an unregistered accountant cannot give you a valid statutory audit opinion. This is the first check in our guide to choosing an audit firm.
The Three Tiers of Audit Firms in Singapore
Every registered audit firm meets the same professional standards, so the real difference between them is scale, network, fee level, and the kind of company they are built to serve. The market falls into three broad tiers.
The table below compares them on the points that matter most when you are choosing.
| Factor | Big 4 | Mid-tier | Boutique / SME-focused |
|---|---|---|---|
| Typical annual fee | S$15,000 and above | S$5,000 to S$15,000 | S$1,500 to S$5,000 |
| Well-known names | Deloitte, EY, KPMG, PwC | RSM, BDO, Baker Tilly, Foo Kon Tan, Crowe, Forvis Mazars, Grant Thornton | Many small registered public accounting practices |
| Best for | Listed companies, large or complex groups, MNCs, IPO and regulated sectors | Established SMEs, regional or group reporting, IPO-track companies | Small and owner-managed companies, dormant or exempt entities needing an audit |
| International network | Global, in every major market | Global network member firms | Usually local only |
| Partner attention for an SME | Lower, work led by managers and juniors | Moderate to high | Highest, often the partner directly |
| Recognition with banks and investors | Strongest | Strong | Adequate for most local needs |
The fee bands above are typical published market ranges for a recurring statutory audit, not fixed prices. The chart below shows how they compare.
The Big 4: Deloitte, EY, KPMG and PwC
The Big 4 are the four largest professional services networks in the world and audit most of Singapore’s listed companies and largest businesses. They are the natural choice when your company is listed on the SGX, is part of a multinational group, is preparing for an initial public offering, or operates in a heavily regulated sector such as banking or insurance. Their brand carries weight with international banks and investors, and they have deep sector specialist teams. The trade-off is cost and, for a small company, less direct partner time. For most SMEs a Big 4 audit is more than the situation requires.
Mid-Tier Firms: RSM, BDO, Baker Tilly and Others
Below the Big 4 sits a band of well-established firms that belong to global networks but cost considerably less. RSM Singapore is the largest professional services firm outside the Big 4 in Singapore. Other recognised names include BDO, Baker Tilly, Foo Kon Tan, Crowe, Forvis Mazars (formerly Mazars), Grant Thornton and CLA Global TS (formerly Nexia TS). These firms suit established SMEs, companies with regional operations or group reporting, and businesses on an IPO track that want a credible name without Big 4 fees. You get an international network and sector experience with more accessible partners.
Boutique and SME-Focused Firms
Most audit firms in Singapore are smaller registered public accounting practices that focus on local SMEs, owner-managed companies, and dormant or exempt entities that still need an audit for a lender, a grant, or a shareholder. They typically offer the lowest fees and the most direct partner attention, which suits a company with a simple structure. The trade-off is a narrower industry range and no global network, so they are less suited to complex groups or cross-border reporting. If your company is small and straightforward, a boutique firm is often the most cost-effective choice.
How Much Does an Audit Cost?
Audit fees are negotiated, not regulated, and they vary widely with the size and complexity of your company. As a rough guide, a boutique firm might charge a small company S$1,500 to S$5,000, a mid-tier firm S$5,000 to S$15,000, and a Big 4 firm S$15,000 or more, with complex groups higher still. The main drivers are revenue, the number of subsidiaries to consolidate, transaction volume, inventory, and the quality of your bookkeeping. For a full breakdown by company profile, see our guide to how much a statutory audit costs in Singapore.
How to Choose Between Them
Once you have confirmed you need an audit and verified that a firm is ACRA-registered, the choice comes down to fit. In our experience helping SMEs, the most common mistake is over-buying: paying for a Big 4 name a smaller firm could match, or paying for an audit the company was exempt from in the first place. Match the firm’s size to your company, look for relevant industry experience, ask who will actually do the day-to-day work, and get a clear written scope and fee so there are no surprises. Our director’s guide to choosing an audit firm walks through each step, and if you are also weighing accounting providers, our roundup of the best accounting firms in Singapore and our guide on how to choose an accounting firm cover the wider corporate-services market.
Clean, audit-ready books make the whole process cheaper and faster, whichever firm you pick. That is where good outsourced accounting and a clear understanding of bookkeeping versus accounting pay off, and where your year-end runs smoothly if you have prepared for your financial year-end in advance.
Frequently Asked Questions
What are the top 4 audit firms in Singapore?
The top four are the Big 4: Deloitte, EY, KPMG, and PwC. They are the largest audit and professional services networks in Singapore and globally, and they handle most listed-company and large-group audits. For a smaller company, however, the best firm is usually a mid-tier or boutique practice that fits your size and budget.
What is the difference between Big 4 and mid-tier audit firms?
Big 4 firms are the four largest global networks and command premium fees, brand recognition with international investors, and deep specialist teams. Mid-tier firms such as RSM, BDO and Baker Tilly also belong to global networks and meet the same auditing standards, but cost less and usually give an SME more partner attention. For most SMEs a mid-tier or boutique firm is the better value.
Do I need a Big 4 firm to audit my SME?
Almost never. A Big 4 audit is valuable when you are listed, raising significant external investment, or part of a multinational group that requires it. A statutory audit from any ACRA-registered firm is equally valid in law, so most SMEs are better served by a mid-tier or boutique firm at a fraction of the cost.
Is RSM one of the Big 4?
No. The Big 4 are only Deloitte, EY, KPMG and PwC. RSM is the largest firm outside the Big 4 in Singapore and is usually described as the leading mid-tier or next-tier firm. It is a strong choice for growing companies that want a recognised global network without Big 4 pricing.
How do I check that an audit firm is registered with ACRA?
Ask the firm for the name of the Public Accountant who will sign your audit report and confirm that the person and the public accounting entity are registered with ACRA. ACRA maintains the register of Public Accountants and public accounting entities and monitors audit quality. If a firm cannot confirm a registered Public Accountant will sign off, the audit will not be valid.
Can my company skip the audit entirely?
Yes, if it qualifies. A private company that meets at least two of the three small-company tests across its last two financial years, and whose group also passes if it is part of one, is exempt from a statutory audit. A dormant company is also exempt. If you qualify, you still prepare financial statements but you do not pay for an audit.
Talk to Us
Choosing an auditor is easier when your accounts are in order and you know whether you even need one. Excellence Singapore helps SMEs confirm whether they qualify for audit exemption, prepare audit-ready financial statements and accounting, and liaise with an appointed audit firm so the process is smooth. We are a corporate services firm, not a statutory auditor, so our advice on which way to go is independent. Talk to us and we will point you to the right path.
