About the Firm
A Legacy of Trust, Built One Client at a Time.
For over 25 years, Croonen Dienstverlening & Associates has delivered precision financial counsel to businesses and individuals who demand the highest standards of expertise and discretion.
Our Story
Founded on Principle. Grown on Performance.
Croonen Dienstverlening & Associates was established by Antonius Petrus Theodorus Croonen — known professionally as APT Croonen — with a singular conviction: that clients deserve more than compliance. They deserve a strategic partner who treats their financial future with the same care as their own.
What began as a boutique practice has grown into a full-service accounting and advisory firm serving over 500 clients. Our growth has been deliberate — driven not by volume, but by the depth of relationships we build and the measurable results we deliver.
Today, Croonen Dienstverlening & Associates is recognized as a trusted advisor to mid-market businesses, professional service firms, real estate investors, healthcare providers, and high-net-worth individuals. The firm remains owner-operated and independent — which means our only obligation is to you.
Mission & Vision
"To provide exceptional accounting, tax, and advisory services that empower our clients to achieve financial clarity, strategic growth, and lasting security — delivered with unwavering integrity and absolute confidentiality."
Our Vision: To be the most trusted financial partner for every client we serve — known not for our size, but for the quality of our counsel and the strength of our relationships.
Mission & Vision
Our Purpose
Integrity
We hold ourselves to the highest ethical standards in every engagement, every recommendation, and every interaction.
Precision
Accuracy is non-negotiable. We verify, validate, and review every figure before it leaves our desk.
Confidentiality
Your financial information is sacred. We protect it with the same rigor we apply to our professional work.
Partnership
We invest in understanding your goals so we can serve as a true strategic partner, not just a service provider.
Our Team
The Partners Behind Your Success
APT Croonen leads every engagement personally, supported by a team of specialized associates committed to client excellence.
APT Croonen
Founder, CEO & Owner
CPA, MBA
Antonius Petrus Theodorus Croonen — known as APT Croonen — founded Croonen Dienstverlening & Associates with a singular conviction: that clients deserve more than compliance, they deserve a strategic partner. With over 25 years of experience in tax strategy, corporate advisory, and financial planning, APT personally oversees every client engagement. He holds a CPA license and an MBA, and is a member of the American Institute of CPAs (AICPA). His hands-on approach and deep commitment to client outcomes set the firm apart from larger, impersonal practices.
Catherine M. Lowe
Associate, Tax & Advisory
CPA, JD
Catherine leads the firm's tax planning and estate advisory practice, specializing in complex multi-entity structures, trust and estate planning, and high-net-worth individual services. A licensed attorney and CPA, she brings a uniquely comprehensive perspective to every engagement.
David A. Thornton
Associate, Audit & Assurance
CPA, CFE
David leads the firm's audit and assurance practice, with deep expertise in financial statement audits, internal controls assessment, and regulatory compliance for mid-market businesses. A Certified Fraud Examiner, he brings rigorous analytical discipline to every engagement.
Credentials & Standards
Professionally Certified. Rigorously Maintained.
Certified Public Accountant (CPA)
Licensed and in good standing with the applicable state board of accountancy.
AICPA Member
American Institute of Certified Public Accountants — upholding the highest professional standards.
GAAP Compliant
All financial reporting prepared in accordance with Generally Accepted Accounting Principles.
IRS Authorized e-File Provider
Authorized to file federal and state tax returns electronically on behalf of clients.
SOC 2 Security Practices
Client data protected under SOC 2-aligned security controls and encryption standards.
Continuing Professional Education
Annual CPE requirements met and exceeded to stay current with evolving tax law and standards.
Ready to Work with Our Team?
Schedule a confidential consultation with one of our senior partners and discover how Croonen Dienstverlening & Associates can serve your financial goals.