About Us

Our History

Grimbleby Coleman Advisors & Accountants is an accounting and business advisory firm headquartered in Modesto, California. Since 1973, we have been trusted by the families and businesses in the heart of the Central Valley to tackle challenges with skill, insight, and experience. We have specialized knowledge in the areas of agriculture, construction, and real estate. Our team is dedicated to building long-lasting partnerships with our clients, community, and each other.

  1. 1973

    Roy’s (Grimbleby) Bookkeeping and Tax Practice opens.

  2. 1981

    Clive Grimbleby purchases his father’s company, Roy’s Bookkeeping and Tax Practice, and Clive Grimbleby, CPA, is formed.

  3. 1986

    Herbert Hamby, CPA, and Clive Grimbleby become partners, and firm is renamed Grimbleby & Hamby CPAs.

  4. 1989

    Jeff Coleman, CPA, comes onboard leading GC to its namesake, Grimbleby Coleman CPAs.

  5. 2008

    Grimbleby Coleman CPAs merges with Dunker & Aced CPAs

  6. 2021

    Ian Grimbleby becomes Managing Partner. Ristau & Co. merges with Grimbleby Coleman CPAs.

  7. 2023

    Grimbleby Coleman celebrates 50 years with a brand refresh and updating our firm name to Grimbleby Coleman Advisors & Accountants.

Client Testimonials

BDO Alliance USA

BDO Alliance

We are an independent member of the BDO Alliance USA, a nationwide association of independently owned local and regional accounting, consulting and service firms with similar client service goals. By supplementing our services, the BDO Alliance USA allows us to:

  • Enhance our client services and broaden our capabilities overall
  • Expand our domestic and international coverage
  • Gain greater technical knowledge in specialty areas
  • Utilize professionals with experience in a wide range of industries
  • Access the most up-to-date technical information
  • Participate in the latest training programs
  • Provide our clients with key contacts and sophisticated professionals throughout the U.S.

Awards and Recognitions

As GC celebrates 50 years in business, we would like to thank our incredible team. For us, our motto, “it’s the people behind the numbers®,” means listening and learning how to cultivate the right conditions to help team members meet their highest potential and, in turn, better serve our clients. We owe this win to our people — our greatest asset!

GC is proud to be recognized among Inside Public Accounting’s Fastest Growing Firms for 2023! This recognition is a testament to our team’s drive for excellence in service, efficiency, and innovation, as well as the trust and support of our valued clients.

GC IPA Top 300 Logo

On to the next level: GC has joined the ranks of Inside Public Accounting’s Top 300 firms in the nation! We are ever grateful to our team and clients for this wonderful milestone!


We have a saying here at the firm–“it’s the people behind the numbers®.” As our firm size climbs each year, so does our culture, knowledge, and resilience through challenging times. The more we grow, the harder we work to never lose sight of the value that each and every team member brings to the table. We owe our achievements to our greatest asset… our people behind the numbers.

GC is pleased to announce our ranking as one of Accounting Today’s Best Accounting Firms to Work For! The firms on this list represent the best workplaces in the accounting profession. It is an honor given only to 100 firms nationwide and it’s the people behind the numbers who make the magic happen and who work hard to build our culture. Thanks for voting for us and for recognizing GC as an outstanding place to build a career and grow!

GC is proud to announce that our growth is in more than firm size. For the first-time ever, we’ve received the esteemed accolade for making IPA’s 2021 Fastest Growing Firms list. This list is based on the 2021 annual INSIDE Public Accounting Survey and Analysis of Firms. Here’s to our team and to building the momentum to keep us moving up the ranks!

The world changed dramatically in 2020, and like many others, we knew it was time to “rethink” things. We were honored to receive the Client Experience Award at the BDO Alliance Rethink Conference thanks, in part, to the introduction of new pricing based on value rather than time, empowering clients to make their own choices. Our work shoring up our onboarding process to provide clarity from day one continues to help us build success for and connections with our colleagues, clients, and community…it’s the people behind the numbers.

On November 18, 2020, the 10th Annual National Philanthropy Day, Grimbleby Coleman was honored to receive the esteemed Outstanding Business Philanthropist Award by the Yosemite Chapter of the Association of Fundraising Professionals! We proudly support our cherished non-profit partners, especially in times of great need. For GC, it’s not just about relationships — it’s about doing what’s right, building trust, and making sure the community knows they can “count on us!” 

GC was pleased to receive an Honorable Mention recognition for Exceptional Client Service at BDO’s 2020 Redefining Excellence Awards in May of 2020! Our approach to excellent service begins with a mindset: client-centric and forward-thinking beyond “just the numbers,” by listening, understanding, and providing transparency to meet the unique needs of every business and individual we serve!

In 1994, IPA began naming the top 50 Best of the Best Firms in the U.S., selected exclusively on their performance in specific areas of management, growth and strategic vision. These Best of the Best firms are some of the highest-performing public accounting firms in the country. We are proud to be counted again among the top 400 firms in the nation since 2018. 

Workplace happiness is not a myth and we have some people to thank for proving it! We’re beaming with pride over earning the honor of “Best Places to Work” for our fourth consecutive year—not easy when every year the bar raises higher and new challenges arise. A great deal of work goes into creating a safe environment and positive workplace culture for employees where everyone’s voice is heard. Thank you, team, for voting Grimbleby Coleman one of the Best Places to Work in the Central Valley and thank you, Opportunity Stanislaus, for putting together this extremely beneficial program for both employers and employees!

Our incredible staff has once again made their voices heard, and we have been named a Best Places to Work: Central Valley awardee-for the third consecutive year! At Grimbleby Coleman, we recognize that a thriving business starts at home. That’s why you can count on us to work every day to create an environment in which our employees feel appreciated and welcome to contribute to our growth. After all, if it wasn’t for them, we wouldn’t be here! We are once again humbled and grateful to our team members for their commitment to us and making us a 2019 designee.

Thanks to our wonderful staff, we now have the privilege of saying we have won the designation of Best Places to Work two years in a row! We wholeheartedly believe that creating a great workplace for our employees is critical to the success of our business.  Happy employees equates happy clients!  Thank you to our staff for their dedication to Grimbleby Coleman and for the 2018 designation.

We were honored to receive the 2018 Mujeres Latinas de Stanislaus Community Champion award for our dedication and support to the Latino community.  Mujeres Latinas de Stanislaus supports the community through student scholarships, quarterly motivation lunches for women and youth education conference.

We are privileged to be awarded the 2017 Chamber Member of the Year Award! Being a locally-owned private business, we understand that there is a symbiotic relationship between our success and the success and growth of other locally-owned businesses. For us, this has meant serving on the Chamber of Modesto’s board for a number of years and ensuring that we are not only networking with key business leaders but also supporting the goals of the chamber. Whether we are sponsoring a chamber event or one of the many important non-profits in our community, we are committed to giving our time and resources so that our community can thrive in job creation, education, and business.

We have the privilege of being named one of the 2017 Best Places to Work: Central Valley! Our employees participated in a confidential survey answering questions relating to our firm’s leadership and planning, company culture and communications, professional training and employee benefits. We couldn’t have won this award without our employees feedback and over 87% response rate! We value our team greatly and thank them for choosing Grimbleby Coleman  as their home away from home!

For our commitment to serving our community, the California Society of CPAs (CalCPA) named us the recipient of its 2016 Public Service Award for Firms.  CalCPA annually presents the award to recognize a firm for its public service contributions at the local, state or national level. In 2015, our employees participated in over 1,680 hours of community service and were board members of over 25 local non-profits, including Love Modesto, the Stanislaus Community Foundation, United Samaritans, Historic State Theatre and Community Hospice.   Beyond board participation, we sponsor over 60 community related events that support our United Way, Community Hospice, Salvation Army and numerous worthwhile non-profits benefiting our community. At Grimbleby Coleman CPA’s, public service is the way we connect with our colleagues, clients and the community we serve, without it we wouldn’t be the “people behind the numbers.”