Theorem Co

Founded by Cerissa Marshall - Chartered Accountant, Registered BAS Agent, Six Seconds EQ Practitioner, Dare to Lead™ trained, and a graduate of the INSEAD Management Acceleration Program - Theorem is built on real-world experience and a genuine understanding of what business owners need. From grassroots bookkeeping at 17 to managing billion-dollar mergers and large-scale system transformations, Cerissa’s background gives Theorem its unique depth and perspective. Whether you're dealing with cash flow stress, scaling challenges, systems needing attention, or team dynamics, we provide practical, calm, and considered support. How We Help: Strategic Business Advisory - Helping business owners make informed decisions with clear financial data and actionable insights- Business process reviews and efficiency optimisation to maximise internal resources- Identifying cash flow bottlenecks and creating sustainable financial solutions. Financial & Operational Optimisation - Budgeting, forecasting, and financial modelling to support growth strategies-Corporate governance, compliance, and risk management- Basic bookkeeping, tax agent duties, and accountancy services to ensure financial accuracy and compliance- System integration and automation to streamline operations, improving efficiency and reducing manual tasks. Business Mentoring - Acting as a sounding board for business owners navigating challenges in leadership, Human Resources, systems and financial decision-making- Providing practical, real-world insights that go beyond traditional accounting- Leveraging an extensive network of industry specialists to connect clients with the right resources. We offer a complimentary discovery call as the first step in every new working relationship. This helps her get a clear understanding of your current challenges and priorities, and how we can help. To book a call, please message us here, or head to our website below.