About us

Founded to serve small businesses and individuals with approachable financial expertise, Avanza Tax & Business Solutions combines technical accuracy with personal service. Sofia Birelas leads a dedicated team of experienced professionals who focus on clarity and measurable outcomes. We prioritize educating clients about tax strategy, reducing stress around filings, and creating financial systems that support sustainable growth, better cash management, and smarter long-term decisions. Our approach integrates cloud accounting tools, routine reconciliations, and scheduled reviews so clients receive timely insights rather than unexpected surprises.

Based in Fairfield, CA, Avanza maintains deep ties to the local business community and neighboring regions. We understand state-level requirements and regional tax nuances, and we work closely with local bankers, payroll processors, and advisors to coordinate services. Our proximity allows for prompt support, in-person consultations when needed, practical understanding of regional business challenges, and tailored solutions aligned with local market conditions. We also prioritize secure document handling and transparent pricing so local clients know what to expect and receive dependable support.

Choosing to work with Avanza means partnering with professionals who translate complex tax and accounting topics into actionable steps. We emphasize timeliness, responsive communication, and tailored solutions to each business model. From onboarding to ongoing support, our goal is to reduce administrative burden, strengthen internal financial controls, and help clients pursue growth with confidence, clarity, and measurable improvements to profitability. We continually refine processes, invest in staff training, and leverage technology to deliver efficient service while maintaining a personal touch that clients value.