A third party fundraiser is a company, organization or individual that holds a promotion, event, or sale to benefit a nonprofit without the nonprofit's participation. Often times, before an individual, company, or team may proceed with holding a third-party event and/or promoting it, they must notify and fill out an agreement provided by the nonprofit to have permission to use the nonprofit's name or logo in association with the event.
You are not a third-party fundraiser if you are a board member, staff member, or registered volunteer of a nonprofit.
Most often, third-party fundraisers are registered participants of races or runs who fundraise independently with their own team's events to benefit an organization, without the beneficiary organization's staff being involved in the planning and execution. Companies who dedicate proceeds of their own event to a cause are usually also considered third-party fundraisers.