In 2025, many US accounting firms are shifting their focus from internal teams to outsourced accounting and tax outsourcing services to reduce operational costs, meet deadlines faster, and maintain regulatory compliance. Amid a nationwide talent shortage and rising client expectations, CPA firms are increasingly seeking the best CPA outsourcing services to stay competitive.
Whether you’re looking to scale during tax season, streamline operations, or simply access skilled offshore talent, outsourcing tax preparation and accounting functions has become a strategic imperative. In this article, we spotlight the top tax outsourcing companies and accounting partners that US CPA firms are relying on in 2025.
Why CPA Firms in the USA Are Turning to Outsourced Accounting
Here’s why more CPA firms have hired offshore CPAs and are embracing outsourced tax and accounting services:
- Scalability: Partnering with an outsourced accounting service provider helps US CPA firms ramp up or down their workload during busy seasons without the overhead of hiring and training new staff.
- Specialized expertise: Outsourcing service providers have a deep pool of resources specializing in US GAAP, IRS regulations, and industry-specific standards, which helps CPA firms gain instant access to specialized expertise without investing heavily in hiring specific talent.
- Efficiency and Speed: Outsourced accounting providers are primarily based at different geographical locations, which enables CPA firms to work across time zones and achieve quick TAT (Turn Around Times) and real-time support.
- Advanced technology: Today’s tax outsourcing companies have a rich technology ecosystem with advanced accounting software, automation, and secure cloud platforms, which enables them to integrate with your existing teams and deliver work smoothly and seamlessly.
- Focus on client service: Partnering with outsourced accounting providers frees your in-house teams to focus on advisory and relationship management without getting bogged down by routine compliance work.
Top 10 Outsourced Accounting & Tax Outsourcing Companies for CPA Firms
Here’s a curated list of the best CPA outsourcing services in 2025, trusted by hundreds of CPA firms in the USA:
Best for: CPA firms needing scalable tax and accounting outsourcing solutions
With over 50 years of rich accounting and bookkeeping expertise, Datamatics CPA is one of the most prominent providers of digitally enabled outsourcing services for more than 200 US CPA firms. Datamatics CPA offers a comprehensive suite of CPA-focused services—accounting, bookkeeping, tax preparation, audit & assurance, and M&A research—tailored by the American regulatory environment. Their outsourcing solutions can be easily scaled up or down to meet seasonal requirements, are technology-driven, and are compliant with US and international GDPR standards.
Datamatics CPA is recognized for delivering outstanding workflow automation, a specialized talent pool, and a focus on compliance, making them the preferred choice for US CPA firms seeking meticulous, secure, and efficient outsourcing.
2. Infinity Globus
Infinity Globus is known for its customized CPA outsourcing solutions for US firms. They offer dedicated teams that specialize in American practices and offer scalable services in tax, accounting, and compliance, helping their clients expand client capacity without compromising on quality.
3. Deloitte
A globally recognized name, Deloitte offers comprehensive accounting outsourcing solutions tailored to US CPA firms. They specialize in audit, tax, advisory, and digital transformation, with a strong focus on compliance and risk management for American CPA firms.
4. KPMG
KPMG’s US-focused accounting outsourcing services encompass a wide range of services, including accounting and bookkeeping, financial analysis, and complex tax compliance. They offer deep industry and US regulatory expertise, offering outsourcing solutions that are perfectly tailored for US CPA firms.
5. PwC
PwC’s comprehensive suite of outsourcing services tailored for US CPA firms includes auditing, tax, and advisory. They deliver absolute compliance with US standards and scalability, which makes them a trusted partner for CPA firms of all sizes.
6. EY (Ernst & Young)
EY is one of the most prominent technology-driven outsourcing service providers specializing in US tax and accounting regulations. Their outsourcing solutions are designed to deliver complex, cross-border, and multi-state accounting and bookkeeping solutions efficiently.
7. Grant Thornton
Grant Thornton has a strong foothold in serving mid-market US CPA firms. They specialize in offering audit, tax, and advisory outsourcing services with a deep focus on industry-specific compliance and client service excellence.
8. IBM
IBM harnesses the power of advanced analytics, AI, and automation to deliver modern, efficient accounting outsourcing for US CPA firms. With a strong focus on technology-first solutions, they help CPAs in the US streamline their workflow and strengthen their data security.
9. Genpact
Genpact offers finance and accounting outsourcing with a strong emphasis on digital transformation for US CPA firms. With a strong suite of technology-driven solutions, they specialize in process optimization and automation capabilities, which help CPA firms modernize their operations and lower their overhead costs.
10. Infosys BPM
Infosys BPM is a global leader in delivering scalable, technology-enabled accounting outsourcing services to US CPA firms. They have a strong focus on automation, analytics, and compliance with American standards.
Key Outsourcing Trends for US CPA Firms in 2025
If you’re a CPA firm looking for a suitable outsourcing service provider to improve your practice, here are a few outsourcing trends that can help you make your decision fast.
- AI and Automation: US CPA firms are aggressively harnessing AI-powered tools for faster account reconciliations, automated data entry, and predictive analytics.
- Cloud-Based Collaboration: When outsourcing, you need real-time access to all your sensitive data and partnering with an outsourcing service provider that offers secure, cloud-based accounting platforms can enable it all for you.
- Regulatory Compliance: Regulatory compliance must be top of your priority list when looking for an outsourcing partner. Partnering with an outsourcing service provider that has the necessary compliance certifications can help you meet evolving US compliance standards without investing heavily in it.
- Customizable Service Models: US CPA firms need flexible, tailored outsourcing services to keep up with evolving client demands. Thus, you must ensure that your outsourcing partner can adapt to your unique workflows and client needs.
- Global Talent, Local Expertise: Most outsourcing service providers offer a perfect blend of international talent pools with US-focused teams. This allows you to gain local expertise without incurring significant costs to acquire it.
Conclusion
Outsourced accounting and bookkeeping services help US accounting firms unlock unmatched levels of efficiency, scalability, and world-class expertise. The top 10 outsourced accounting firms for US CPA firms in 2025 that we have listed are just a few of the prominent names that US CPA firms are harnessing to gain proven, compliant, and technology-driven solutions tailored for the American market.
If you are looking to transform your CPA firm or expand your service offerings by partnering with a prominent outsourcing service provider for your CPA firm in the USA, you can write to us at marketing@datamaticsbpm.com, and we will have our experts reach out to you with solutions that can help you thrive in the rapidly changing industry.
What makes Datamatics CPA one of the best CPA outsourcing services in 2025?
They combine 50+ years of CPA expertise with trained offshore accountants specializing in US tax regulations, helping firms meet deadlines and maintain compliance.
What are the key factors US CPA firms should consider when selecting an outsourced accounting partner?
US CPA firms should prioritize partners with proven expertise in US accounting standards (GAAP), strong data security protocols (such as SOC 2 compliance), experience with leading US accounting software, scalability for seasonal or growth needs, and a track record of serving American CPA firms. Transparent communication, client references, and flexible service models are also essential.
How does outsourcing accounting benefit US CPA firms during tax season?
Outsourcing provides instant access to a larger talent pool, enabling CPA firms to handle increased workloads without the delays and costs of hiring temporary staff. This ensures timely tax preparation and filing, reduces staff burnout, and maintains high service quality even during peak periods.
