Grassi, a provider of advisory, tax, and accounting services, has merged with Massachusetts-based Anstiss & Co.

The move is expected to enhance the firm’s presence in the region and bolster its service offerings to family-owned businesses, nonprofits, and high-net-worth individuals.

The merger will see six partners and 50 professionals and staff from Anstiss join the Grassi team, expanding the company’s expertise and capacity.

Raymond Anstiss will continue as managing partner of the Chelmsford office and take on the new role of Grassi’s Boston market leader.

Raymond Anstiss said: “This is an exciting next chapter for our team.

“Joining Grassi will enable us to deliver even greater value to our clients and provide our team members with opportunities for growth and development on a greater scale, all while preserving the strong relationships and personalized service that are the foundation of our firm.”

How well do you really know your competitors?

Access the most comprehensive Company Profiles on the market, powered by GlobalData. Save hours of research. Gain competitive edge.

Company Profile – free sample

Thank you!

Your download email will arrive shortly

Not ready to buy yet? Download a free sample

We are confident about the unique quality of our Company Profiles. However, we want you to make the most beneficial decision for your business, so we offer a free sample that you can download by submitting the below form

By GlobalData
Visit our Privacy Policy for more information about our services, how we may use, process and share your personal data, including information of your rights in respect of your personal data and how you can unsubscribe from future marketing communications. Our services are intended for corporate subscribers and you warrant that the email address submitted is your corporate email address.

Both firms have committed to maintaining the “high standards of service and technical excellence” and the integrated team will operate under the Grassi brand.

Grassi founder and CEO Louis Grassi said: “Our firms share a mutual commitment to client service excellence and our people.

“As we continue to expand our footprint, we prioritize aligning with firms that share our vision for delivering tailored client experiences and growth-focused solutions.

“This represents another step forward in Grassi’s commitment to being wherever our clients need us most.”

Earlier in January 2025, PrimeGlobal, an association of advisory and accounting firms, added Grassi Advisory Group as a new US member firm.

PrimeGlobal stated that its membership will benefit the firm by offering access to a global network of accounting expertise, essential for businesses expanding internationally.

Additionally, the move allows the firm to meet international business needs, drawing on insights from PrimeGlobal’s global network.