Below is a partial list of Peter's training clients over the past few years.

• National Council For Voluntary Organisations (UK)
• The Deaconess Foundation
• Ronald McDonald House Charities (US and Asia)
• Goodwill Industries International
• Kellogg School of Management (Northwestern University)
• Volunteers of America
• BoardSource
• Volunteer Vancouver
• Workability International
• Hartford Foundation for Public Giving
• Faith In Action
• The Wilder Foundation
• National Council for Community Behavioral Health Care
• National Association for Treasurers of Religious Institutes
• Lutheran Services In America
• The Foellinger Foundation
• Corporation for Public Broadcasting
• Special Olympics, United States
• American Society of Association Executives
• Colorado Behavioral Health Council
• NISH
• Society of Actuaries
• American Institute of Certified Public Accountants
• The Center for Nonprofit Management-Oklahoma
• National Association for the Deaf
• Metro Volunteers - Denver
• Washington State Society of CPAs
• Association of Baptist Foundations
• Alliance for Nonprofit Management
• International Association of Conference Center Administrators
• ASAE San Antonio
• National Association of Homes and Services to Children
• Volunteer Baton Rouge!
• Florida Association of Retarded Citizens
• Amherst Wilder Foundation
• Center for Nonprofit Excellence - Akron
• Evergreen Society
• YMCA of the USA
• Rehabilitation for Wisconsin
• Make-A-Wish Foundation
• National Kidney Foundation
• Iowa Association of Community Providers
• Colorado Association of Nonprofits
• California Association of Nonprofits
• Maine Association of Nonprofits
• Oregon Research Council
• Nonprofit Resource Center of Alabama
• Connecticut Association of Rehabilitation Facilities
• Easter Seals US
• Michigan Association of Rehabilitation Facilities
• United Way of the Quad Cities