How to Build an Audit Career Outside the Big 4

The mid-tier career ladder is not a slower version of the Big 4

Mid-tier firms (Mazars, Baker Tilly, BDO, Grant Thornton, Forvis, or the smaller SRA-member practices) are not a diluted version of the Big 4 career path. The structure is different in ways that work in your favour if you understand them.

At a Big 4 firm, the path is associate to senior to manager to senior manager to director to partner. Each step has a fixed timeline (roughly 2-2-3-3 years), a large cohort competing for the same promotions, and a client portfolio you inherit rather than build. By the time you reach manager, you’ve spent five years on engagements where the client relationship belongs to someone two levels above you. Your technical knowledge might be deep, but your commercial experience is shallow. That asymmetry takes years to correct.

At a mid-tier firm, the timeline compresses. Senior in 2 years is typical. Manager in 4-5. But the nature of the role changes earlier. A manager at an SRA-member practice with 40 staff runs client relationships that a Big 4 senior manager wouldn’t touch until year 8 or 9. You sign engagement letters. You present to audit committees. You manage the fee discussion. You draft the management letter. This isn’t faster promotion for the same work. It’s different work, earlier.

The trade-off is real and you should weigh it with your eyes open. Big 4 experience carries brand weight in recruitment. A CV that says “Deloitte” opens doors that “Koenen en Co” does not, regardless of what you actually did. But brand weight decays over time. After 5 years of post-qualification experience, recruiters and hiring managers care about what you can do and whether you hold the RA. Your former employer’s name becomes background noise. What persists is your client book and your specialisation. Those are the assets that don’t have an expiry date.

If you’re already at a mid-tier firm, stop measuring your career against the Big 4 timeline. Measure it against the capabilities you’re accumulating: client management by year 4, RA completion by year 6 at the latest. The risk of a SALY approach to career progression (same as last year, no deliberate change) is that you wake up at year 7 with a title bump but no portable skill set. Those capability milestones matter more than your title.

Why specialisation matters more outside the Big 4

At a Big 4 firm, the brand does the differentiation. Clients hire PwC because it’s PwC. At a mid-tier firm, the client hires you (or your partner) because you know their industry or their regulator. Specialisation is how mid-tier auditors build market value that isn’t attached to an employer.

A generalist manager at a mid-tier practice is billable at whatever the standard rate allows. A specialist who can run ISAE 3402 engagements bills at a premium because fewer people in the market can do the work. The premium compounds: specialists generate repeat engagements, and repeat engagements build the client book you need for partnership. Generalists, by contrast, risk falling into a “just roll it forward” pattern where the work stays the same year after year and their market value flatlines.

Four specialisation areas carry outsized value in the current Dutch and EU market.

CSRD and sustainability assurance is the most obvious. The Corporate Sustainability Reporting Directive (effective for large PIEs from financial year 2024) requires limited assurance on sustainability reports under ISAE 3000 (Revised). The Big 4 firms are building dedicated ESG assurance teams. Mid-tier firms that can offer this service capture clients who don’t want Big 4 pricing but need assurance that satisfies the Directive. The auditor who understands both ISAE 3000 and ESRS E1 through S4 is rare at any firm size. At a mid-tier firm, that knowledge makes you irreplaceable rather than one of forty people on a practice group email list. The ciferi CSRD assurance guide covers the standard requirements in detail.

ISAE 3402 (service organisation controls) is a specialisation with particularly strong demand among Dutch mid-tier firms. Payroll companies, SaaS providers, pension administrators, and managed service providers all need Type II reports. The Big 4 handle ISAE 3402 engagements for their largest clients but rarely pursue smaller service organisations (€5M-€50M revenue). That market belongs to mid-tier and SRA-member firms. If you can run an ISAE 3402 engagement from planning through the Type II report, you’re billable on work that has a 12-month recurring revenue cycle.

IT audit and IT general controls (ITGCs) is a skill set that mid-tier firms chronically understaff. ISA 315 (Revised 2019) expanded the requirement to understand the client’s IT environment, including identifying IT applications relevant to financial reporting, IT general controls, IT process flows, and automated controls within business processes. In practice, mid-tier audit teams with fewer than 60 staff almost always rely on IT audit specialists from external providers (like the Big 4’s own IT audit arms, ironically). Building ITGC competence in-house carries direct fee value. An auditor who can assess a client’s ERP access controls, change management procedures, backup/recovery processes, and segregation of duties configurations without calling in an expensive external specialist saves the practice €2,000-€5,000 per engagement in subcontracted IT audit fees.

Financial services regulation is the fourth area. AFM-regulated entities (investment firms, fund managers, payment service providers) have specific audit requirements under the Wet op het financieel toezicht (Wft). Mid-tier firms with AFM expertise compete directly with Big 4 on smaller licensees. The regulatory barrier to entry protects the specialisation because you can’t just read the Wft and claim competence. It requires engagement experience with regulated entities, and that experience accumulates faster at a mid-tier firm where you work on more engagements per year.

The RA qualification as a career moat

The Registeraccountant qualification in the Netherlands is not a credential you collect and file. It’s a regulatory licence. Only an RA (or an equivalent like an AA with the right registration) can sign a statutory audit opinion under Dutch law. This is codified in the Wet toezicht accountantsorganisaties (Wta).

Every audit firm needs RAs. The supply of qualified RAs has been declining relative to demand for years, because fewer students complete the programme and more qualified accountants leave practice for industry. The NBA’s annual membership data shows this trend consistently. An RA who can run engagements is structurally scarce. And structural scarcity, unlike cyclical scarcity, doesn’t correct itself quickly.

If you’re at a mid-tier firm and you hold the RA, your negotiating position improves with each year of post-qualification experience. You’re not one of 300 managers at a Big 4 firm competing for 30 partner slots. You’re one of maybe 8-12 qualified staff at a practice that needs you to sign opinions. The economics are different. When the AFM inspects your firm and checks engagement partner (EP) qualifications, your RA number is what appears on the file. Not the practice name.

Complete the RA programme as fast as your study load allows. Every month of delay is a month where you don’t have the licence that makes you structurally valuable. The theoretical exams are a bottleneck for roughly two-thirds of candidates. Clearing them in the minimum number of sittings should be the priority, even if it means less social time during study periods.

Once qualified, invest your development time in specialisations that make your RA more valuable, not in generic “leadership training” that every firm offers. A qualified RA who can sign ISAE 3402 reports and understands CSRD assurance has a market value ceiling significantly above a qualified RA whose only differentiation is having worked at the same firm for ten years. The qualification is the floor. What you build on top of it determines the ceiling.

The ciferi ISA 220 quality management guide is relevant here because ISA 220.13 places specific responsibilities on the EP, which is the role your RA licence grants access to.

Worked example: two career paths from the same starting point

Starting point: Two auditors, both 24 years old, both starting their RA programme. Auditor A joins a Big 4 firm in Amsterdam. Auditor B joins a 45-person SRA-member firm in Rotterdam. Both are competent and motivated, and both plan to stay in audit for at least six years.

Exit paths and salary benchmarks

After 4-6 years at a mid-tier firm with an RA qualification, four exit paths carry the highest market value.

Staying and making partner at a mid-tier firm is the path fewer than one in five mid-tier managers seriously consider because Big 4 culture frames “staying” as settling. At a 40-80 person practice, partner typically requires a portable client book of €300,000-€600,000 in annual fees and 8-12 years of experience. Partner income at SRA-member firms ranges from €120,000 to €250,000 depending on firm size, location, profit share structure, and client mix. This isn’t Big 4 partner income, but the capital buy-in is lower and the work-life balance is measurably better. Partners at mid-tier firms typically manage 15-25 audit clients directly, which creates a different kind of professional life than the Big 4 model of managing managers who manage engagements.

Moving to a larger mid-tier firm is the lateral upgrade. BDO, Grant Thornton, Mazars, and Forvis hire experienced managers and senior managers from smaller firms to fill gaps in their teams. An RA with an ISAE 3402 or CSRD specialisation commands a premium in lateral moves. Salary uplift of 10-15% is typical, and the move often comes with a faster partnership track because you’re filling a specific need rather than joining a general cohort.

Moving to industry as an internal audit manager or finance manager is the exit roughly 40% of mid-tier leavers take. Companies in the Netherlands with revenue above €50M increasingly require internal audit functions or at minimum a finance manager with audit experience who can manage the external audit relationship. An RA with engagement management experience is a strong candidate for these roles. Salary range: €80,000-€110,000, plus the significant lifestyle difference of no busy season. The trade-off is that industry roles don’t accumulate in the same way. A partner at a mid-tier firm builds equity and a client book over time. An industry finance manager earns a salary.

Joining an audit technology company in a client-facing role is a newer exit path but growing fast. Companies like TeamMate, CaseWare, Silverfin, and DataSnipper hire people who understand audit workflow from the inside. The combination of RA qualification and practical engagement experience is exactly what these companies need for product management, pre-sales, customer success, and implementation consulting roles. Salary varies widely (€70,000-€120,000 depending on role and company stage) but equity or bonus structures change the total compensation picture. For auditors who are technically inclined, this path offers the rare combination of audit domain knowledge and technology exposure.

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Related content

• CSRD assurance requirements. Full guide to the assurance requirements under the Corporate Sustainability Reporting Directive, including the ISAE 3000 framework and what auditors need to know.
• ISA 320 materiality calculator. Free tool for calculating overall and performance materiality under ISA 320 , relevant for any audit engagement regardless of firm size.
• ISAE 3402 audit template pack. Complete engagement file template for ISAE 3402 Type I and Type II engagements, built for mid-tier firms.

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