O'Donnell & Dennis, CPAs, LLC is a Longmont, CO accounting firm serving individuals and business clients with tax, accounting, and advisory support. Its listed services include tax preparation and planning, bookkeeping, payroll, sales tax, and broader business services for companies that need organized financial operations.

The firm works with small businesses, medium-sized businesses, and freelancers, and its service menu also references support for QuickBooks setup, training, questions, and tune-ups. Business-focused offerings include small business accounting, cash flow management, bank financing, new business formation, succession planning, internal controls, and litigation support.

For tax matters, O'Donnell & Dennis lists individual and business tax preparation, estate and trust tax services, cryptocurrency accounting services, and several forms of tax relief, including IRS audit representation, back taxes owed, payroll tax problems, liens, levies, and payment plans.