Licensed CPA Firm — Arizona
APG Advisory is a full-service CPA firm delivering financial statement audits and compilations, employee benefit plan audits, tax services, bookkeeping, controller and fractional CFO services, accounting cleanup and month-end close, audit readiness consulting, remote audit support for U.S. CPA firms, and SOC 1 & SOC 2 examinations — engineered for growing companies who can't afford to wait.
Who we are
To strengthen trust in the global economy through world-class professional services.
We serve nonprofits, small and medium-sized businesses, SaaS companies, retirement plan sponsors, and other CPA firms across industries throughout the United States — trusted for quality, efficient audit, accounting, and advisory services.
Leadership
Arthur Mthombeni is the Founder and Chief Executive Officer of APG Advisory LLC, a U.S.-licensed CPA firm offering a full range of audit, assurance, accounting, and advisory services. He brings over ten years of audit experience with Big 4 audit firms, where he audited multinational financial services institutions, and leads the firm's mission to help SaaS companies, nonprofits, retirement plan sponsors, small and medium-sized businesses, and other CPA firms build trust, strengthen their finance functions, and stay audit-ready as they grow.
With a professional foundation in accounting, auditing, and risk management, Arthur combines technical assurance expertise — across SOC examinations, financial statement audits, and employee benefit plan audits — with practical, hands-on experience helping clients run their day-to-day finance operations, from month-end close to controller and fractional CFO support.
Arthur is particularly passionate about helping growing organizations professionalize their finance function. He believes that clean books, strong internal controls, and audit readiness are not just compliance checkboxes, but strategic enablers that protect enterprise value and accelerate growth.
Under his leadership, APG Advisory is building a reputation for delivering practical, business-focused services that go beyond a single engagement. The firm's approach emphasizes executive-level insight, technical excellence, and long-term partnerships — whether that means leading an audit, supporting another CPA firm's engagement remotely, or serving as an outsourced controller.
As a lifelong learner, Arthur continually invests in expanding his expertise across audit methodology, accounting operations, governance, and risk management to ensure APG Advisory remains a trusted, full-service partner for its clients. His long-term vision is to establish APG Advisory as one of the most respected CPA firms in its markets, recognized for exceptional technical quality, integrity, and client service.
Services
From audit and assurance to accounting and advisory, we bring the same technical rigor and clear communication to every engagement — whether you're closing your next enterprise deal, reporting to your board, or just trying to close the books on time.
High-quality, seamless SOC examinations that your enterprise buyers respect. We dissect your security posture, identify vulnerabilities, and recommend solutions that actually work — across geographic boundaries.
Premium, tech-driven assurance to uncover valuable insight into your company's finances — financial statement audits, reviews, compilations, agreed-upon procedures, and examinations, sized to the level of assurance you need.
Independent audits of employee benefit plans that satisfy ERISA and DOL requirements, delivered on the timeline plan sponsors and third-party administrators need.
Overflow and outsourced fieldwork support for other CPA firms — we work as an extension of your team, under your engagement, to help you meet busy-season deadlines without adding headcount.
Senior-level financial leadership without the full-time cost. We help growing companies build reliable reporting, cash flow visibility, and controls that scale with the business.
Get your books current, reconciled, and audit-ready. We untangle messy accounting, catch up backlogged books, and build a repeatable month-end close process going forward.
Preparing for your first audit — or trying to make the next one smoother? We help you get your documentation, controls, and evidence organized well before fieldwork begins.
Practical tax preparation and planning for businesses and their owners, coordinated with your accounting and assurance work so nothing falls through the cracks.
Reliable, ongoing bookkeeping so your books stay accurate and current all year — freeing you up to run the business instead of chasing transactions.
Our approach
Four steps. No surprises. Whether it's an audit, a cleanup project, or ongoing controller support.
We assign a team with deep understanding of your tech stack, from start to completion — no rotating staff, no re-explaining your environment.
Weekly status calls and fast response times keep the audit moving — and keep you informed at every stage.
Structured, staged evidence lists eliminate repeat requests and speed up fieldwork significantly.
We hold the engagement — and ourselves — to the agreed schedule, eliminating missed deadlines.
Why APG
Controls aligned to your company's actual maturity level — not a rigid checklist.
You know the full cost before the engagement begins. No surprise invoices.
The people who start your engagement are the people who finish it.
Robust quality-control measures behind every report we issue.
Milestone tracking that eliminates delays before they happen.
Regular updates, not radio silence between kickoff and final report.
Who we serve
Insights
Our insights library is being prepared — check back soon for practical guidance on SOC readiness, audit timelines, and what enterprise buyers actually look for in a report.
Schedule
Pick a time that works for you below — it syncs directly with our calendar, no back-and-forth emails required.
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