Over 30 Years of Helping Businesses Thrive Financially

Throughout Massachusetts and Florida

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I've been servicing companies with their bookkeeping needs for over 30 years. It has been a privilege and an honor to work for some of the most respected CEO's in Massachusetts and Florida.

I believe my extensive experience coupled with my passion to help people will inevitably make your bookkeeping needs a success!

"Creating Order, Inspiring Financial Success"

Jane Belcastro

Jane Belcastro
Owner / Bookkeeper

Schedule a Free Consultation

Bookkeeping Services That Bring Clarity to Your Business

Accounts Payable

For business owners who want to stay organized and never miss a payment, SUM Accounting will handle all your accounts payable needs. Our structured process ensures accuracy and consistency, giving you more time to focus on your business instead of your books.

  • Receive, review, and process vendor bills and invoices

  • Enter expenses accurately and code them to the correct accounts

  • Schedule and issue payments on time (checks, ACH, credit cards)

  • Reconcile vendor statements and resolve billing issues

  • Maintain organized records and documentation

  • Track due dates to avoid late fees and missed payments

  • Communicate with vendors regarding payments and questions

Accounts Receivable

For business owners who want steady cash flow and less stress, SUM Accounting handles your accounts receivable, so you get paid on time. Our structured process ensures timely invoicing and accurate payment tracking, giving you more time to focus on growing your business instead of chasing payments.

  • Create and send accurate customer invoices

  • Record and apply payments correctly

  • Track outstanding balances and due dates

  • Follow up on past-due invoices professionally

  • Resolve billing questions and discrepancies

  • Maintain organized customer and payment records

  • Reconcile receivables and support month-end reporting

Financial Reports

Bring clarity to your financial data with detailed monthly, quarterly, and yearly reports. SUM Accounting provides regular reconciliations, balance sheets, and P&L statements. Our accurate and transparent reports give you the insights you need to make confident financial decisions and maintain full control over your business’s performance.

  • Reconciliations of bank, credit card and loan statements

  • Payroll Reporting

  • Balance Sheet

  • Profit & Loss Statements

  • Class Tracking

  • File and Pay Sales Tax

  • File Annual Reports

  • Maintain accurate digital filing system for each client

  • Provide year-end support for Tax Preparer and CPA’s

  • Customized reporting and cleanup services tailored to each client’s needs

Why Hire Sum Accounting?

It is essential to know how, why and where your revenue and expenses are being allocated. Contracting this portion of your work frees your time to concentrate on what is important, the growth and profitability of your business.

Our clients find that timely financial reports are of great value in determining the financial position of their company, as well as their long-term planning.

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Business Group In A Meeting Room In The Office

Effective Communicator

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Client Focused

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Relationship Building

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Attention to Detail

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Organizational Leadership

Effective Communicator · Client Focused · Relationship Building · Attention to Detail · Organizational Leadership

Effective Communicator

·

Client Focused

·

Relationship Building

·

Attention to Detail

·

Organizational Leadership

Effective Communicator · Client Focused · Relationship Building · Attention to Detail · Organizational Leadership

What Clients Say

  • "Working with Jane at Sum Accounting has been one of the best decisions for our agency. She’s meticulous, reliable, and always delivers on time—we truly see her as part of our team.”

    —Erjon Metohu, President, ERI

  • “Working with Jane Belcastro of SUM Accounting since early 2025 has been an exceptional experience for our practice. Jane quickly became an invaluable partner, bringing clarity, organization, and genuine peace of mind to our bookkeeping operations. What stands out most is her accuracy, responsiveness, and proactive guidance. Jane not only keeps our books in perfect order, she also anticipates our needs, identifies issues before they become problems, and offers thoughtful solutions that help our practice run more smoothly. Her professionalism is matched by her warm, approachable style. We are truly grateful for her expertise and dedication, and we wholeheartedly recommend Jane Belcastro and SUM Accounting to any business seeking reliable, skilled, and personable bookkeeping support.”

    —William M. Foley, D.O., M.Sc., Owner of Boston Osteopathic Health

  • "My name is Giuseppe Ventriglia, and for nearly 50 years I have owned and operated a company called StoneFire Outdoor Living LLC. About 10 years ago, Jane began working with our company as a bookkeeper. It quickly became clear how exceptional she was, and her role naturally expanded to include human resources, marketing, office management, and operational support. She also assisted me with several other businesses not directly associated with StoneFire. Over the years, Jane became truly indispensable to both me and my companies. She handled virtually all office-related responsibilities with outstanding organization, responsibility, and genuine care for others. Because of her dedication and reliability, I had little to no concern about the administrative side of the business, which allowed me to focus on growing and managing other aspects successfully. When I sold the company and Jane decided to start her own business, I fully supported and encouraged her decision. With only a few references, she became successful within just a few months. I continue to work with Jane today, as she still handles the bookkeeping for my properties. She is extremely trustworthy, detail-oriented, and always looks out for my best interests. I would wholeheartedly recommend Jane to any close friend or colleague seeking professional accounting, bookkeeping, or office management services."

    —Giuseppe (Joe) Ventriglia, Owner of Rockon Realty, Former owner of Stonefire Outdoor Living

  • "I am absolutely thrilled to share my heartfelt appreciation for SUM Accounting, whose exceptional professionalism, meticulous attention to detail, and unwavering dedication have been invaluable to my financial management. Their expertise ensures that every transaction is accurately recorded, deadlines are consistently met, and financial reports are clear and insightful. Beyond technical skills, SUM Accounting brings a proactive approach, anticipating potential issues before they arise and offering practical solutions. Their responsiveness and clear communication make collaboration effortless and reassuring. I recommend SUM Accounting to anyone seeking a trustworthy, knowledgeable, and diligent financial partner. Their contribution has not only enhanced my financial accuracy but also provided peace of mind, allowing me to focus confidently on other critical aspects of my work."

    –Jenni Bursell, Owner of Goldstar Consulting

Let’s work together

📞 Call or Text: 508-847-2559

✉️ Email: jbelcastroSA24@gmail.com