Auditing another accountancy firm is not your average engagement. The stakes are high, the standards are exacting, and the professional sensitivities involved demand the utmost care.

 At Williamson & Croft, we understand that auditing a fellow professional services firm, particularly another accountant, requires a delicate balance of independence, technical expertise, commercial understanding, and discretion.

Whether the audit is part of a merger or acquisition, a group reporting requirement, an internal quality review, or regulatory compliance, it must be carried out with absolute objectivity and competence.

In this article, we explore why auditing other accountancy groups is such a specialised discipline, the unique challenges it presents, and how Williamson & Croft is ideally placed to support these assignments with precision and professionalism.

Understanding the Landscape: Why Audit Another Accountancy Firm?

There are several scenarios where a firm like Williamson & Croft might be engaged to audit another accountancy group:

  • As part of a group audit, where a parent company owns several accountancy firms and needs consolidated financial statements reviewed
  • During a merger or acquisition, to assess the financial health, internal controls, and compliance status of the target firm
  • In response to regulatory requirements, such as ICAEW Practice Assurance reviews or file inspections
  • To meet internal governance or shareholder requirements, ensuring financial and procedural integrity within the group

Whatever the reason, these audits come with heightened scrutiny. After all, accountants are usually adept at masking weaknesses or operating within a narrow interpretation of the rules. An audit in this space needs to go deeper.

The Unique Challenges of Auditing Accountants

1. Technical Proficiency and Sector-Specific Knowledge

Auditing an accountancy firm requires not only deep knowledge of accounting and auditing standards but also an insider understanding of how firms operate. From recognising revenue on work in progress (WIP) and debtors, to reviewing fee arrangements, lock-up periods, and recoverability metrics, you need professionals who know what should happen, not just what’s been reported.

At Williamson & Croft, we regularly work with accountancy practices and professional services businesses, giving us a solid grasp of how they manage:

  • WIP and time-based billing
  • Engagement letter compliance
  • Revenue recognition in line with FRS 102
  • Contingent fee arrangements and ethical constraints
  • Tax liability accruals for complex group structures

This familiarity allows us to quickly identify where risks may lie and where figures may not reflect economic reality.

2. Maintaining Professional Independence

There’s an added layer of professional sensitivity when auditing fellow accountants. Independence must not only be maintained, it must be seen to be maintained.

This means:

  • Ensuring no conflicts of interest exist, especially if both firms are part of the same network or share clients
  • Applying a clear separation between advisory or consultancy relationships and audit engagements
  • Being particularly transparent in the engagement scope, methodology, and reporting process

Williamson & Croft ensures full independence protocols are followed from engagement acceptance to sign-off, aligning with FRC Ethical Standards and ICAEW Code of Ethics. We take our independence seriously because in this environment, reputational credibility is everything.

3. Commercial Sensitivity and Confidentiality

Auditing a fellow accountancy group often involves reviewing sensitive internal matters: client profitability, partner remuneration structures, litigation exposure, and file quality. The audit team must navigate this delicately while preserving full confidentiality.

At WC, we use secure client portals, restricted-access data rooms, and strict team protocols to protect your information and your reputation. Our team is trained in managing confidential data, particularly when reviewing engagements involving high-profile or regulated clients.

4. Navigating Quality Control, AML, and Ethical Compliance

Accountancy firms are subject to rules that go beyond financial reporting. When auditing another firm, it’s common to include:

  • Anti-money laundering (AML) process reviews
  • Internal file quality checks
  • Independence and objectivity assessments
  • Ethical standard compliance monitoring

We can either perform these as part of the audit scope or offer them as standalone services—for instance, as a preparatory exercise ahead of an ICAEW Practice Assurance review.

Why Williamson & Croft?

Williamson & Croft is uniquely positioned to support audits of other accountancy practices because:

  • We know the industry inside out. Our team has extensive experience working with accountancy and professional services firms—both as advisors and auditors.
  • We apply a commercial mindset. We don’t just tick boxes—we consider what the numbers mean for governance, profitability, and client retention.
  • We are genuinely independent. We operate outside large global networks, avoiding the common conflicts of interest in this space.
  • We offer partner-led delivery. All our audits are led by senior professionals, ensuring experience, judgement, and direct accountability at every stage.
  • We integrate with your legal, tax, and compliance frameworks. Our multidisciplinary team can support tax structuring, group consolidation, file review, and even valuation advice, where required.

Conclusion: Don’t Leave It to Just Any Auditor

Auditing another accountancy group isn’t just about verifying compliance, it’s about demonstrating transparency, control, and financial robustness to regulators, stakeholders, and commercial partners. In this sector, your auditor’s quality becomes a reflection of your own.

Whether you’re preparing for a sale, navigating group audit requirements, or conducting a cold file review, you need an audit partner who understands the professional services landscape from the inside out.

Choose Williamson & Croft for a robust, discreet, and commercially focused audit of your accountancy firm.

Our specialist team will work with your partners, finance function, and compliance staff to deliver assurance that holds up to the highest standards, professionally, technically, and ethically.

Contact us today to arrange a confidential discussion about your audit requirements or to request a tailored proposal.